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AMATEUR 



RADIO 



NOVEMBER 1977 
S2.00 








the double edge 



for DXers, contesters, 

other advocates of 

the super signal 




WW 



Big Sticker" monobanders 



with double 

driven 
elements 

fun gain, tow VSWR, 

CWIphonB op&tatioit 

without retuniftg. 



and, for a heavy-duty 

rotator that will point 

theni . . . and keep them 

pointed... under tough 

weather conditions, 

use1heKLM-1500HD- 





KLM beams with double driven elements continue to be 
the clioice of amateurs tlirougliout tlie world. They are 
performance proved. . .clearly superior. . .and there are 
good reasons for this superiority. 

Unlike most other multi-element yagis, KLM's "Big Sticker" 
series of monobanders operate at high efficiency over 
the entire CW and phone portions of any given amateur 
band without retuning. Forward gain is high, the pattern 
is clear, VSWR is low across the band limits specified. 
Among other advanced design considerations, KLM uses 
log-periodic techniques with double driven elements to 
assure full excitation and low VSWR on beams covering 
the full 40, 20, 15 and 10 meter amateur bands. In addition, 
the frequency response of KLM "Big Stickers" rolls off 
very rapidly beyond band extremes thereby minimizing 
harmonics and adjacent channel interference. 
These are husky, well constructed beams that use strong, 
lightweight elements and booms of 6063-T832 weather- 
resistant aluminum. Hardware is top quality stainless 
steel. The insulated mounting brackets (pictured below), 
an exclusive KLM design, are molded of GE polycarbonate 
"Lexan," a material that has excellent insulating qualities 
and very high mechanical strength. 



KLM insulating 
support bracket 



Available monobanders: 4 element, 40 meters. 5 and 6 element, 
20 meters. 6 element, 15 meters. 5 and 6 element, 10 meters. 

At your dealer Full specifications on request. 




AIM 



KLIVI1500-HD Rotator 



electronics, inc. 



17025 Laurel Road, Morgan Hill, CA 95037 (408) 779-7363 



niC-S mierofliinicilure lone eAcocler 



.Compatible with aU sub-audible tone systems such as: Private Line, 
Channel Guard, Quiet Channel, etc, 

^^_* Powered by 6-l6vdc, unregulated 
^^* Microminiature in size to fit inside all moblEe units 
and most portabie units 
'Field replaceable, piug-tn, frequency determining elements 

"xelient frequency accuracy and tempe' .^'.-^-^ 

[tput tevel adjustment potentiometer 
w distortion ^^wave output 
'■^^te in alf flA tone frequencies, 67.0H2= 
'"•^ immunity to RF 




■■*^'-^-i'''-Wir< 



?JttitJt^ i 



' *1 



\ 




$29.95 each 

Wirsd and tested, complete with 
K.-1 element 




communicoUon/ /pecicili/t^ 



P.O.BOX 153 
BREA, CALIFORNIA 92621 

(714) 998-3021 



I* »■ 



K-1 FIELD REPLACEABLE, 
PLUG-IN, FREQUENCY 
DETERMINING ELEMENTS 

$3.00 each 



' 5.,?...? ,' 



' ' 



VOL 30L 



flficoM ' ic-fl4B ti/ttoa OOP 



3M FM TEAN^CEIVES 



fJTER •- ^— ^ 
B/R£V SIM 



cw-T *iec MB la 9SB 






i- REC FASf OfF NOfl' fW 



» I 

\l 

Thaf s all, Folks! 

AH you need for All Mode Mobile, that is. 

All Mode Mobile is now yours in a superior ICOM radio that is a generation aheadof 
all others. The new, fully synthesized IC-245/SSB puts you into FM, SSB and CW 
operation with a very compact dash-mounted transceiver like none you've ever seen. 



Variable offset: Any offset from 10 
KHz through 4 MHz in multiples of 
10 KHz can be programed with the 
LSI Synthesizer. 

Remote programing: The IC- 
245/SSB LSI chip provides for the 
input of programing digits from a 
remote key pad which can be com- 
bined with Touch Tone* circuitry to 
provide simultaneous remote pro- 
gram and tone. Computer control 
from a PIA interface is also possible. 

* a f egislered trademark of AT&T. 



SPECIFICATIONS 



VHF/UHF AMATEUR AND MARINE COMMUNICATION EOUrPMENT 



• FM stability on SSB and CW: 
The 1C-245/SSB synthesis of 100 
Hz steps make mobile SSB as stable 
as FM. This extended range of oper- 
ation is attracting many FM'ers who 
have been operating on the direct 
channels and have discovered SSB. 

The IC-245/SSB is the very best and 
most versatile mobile radio made: 
that's all. For more information and 
your own hands-on demonstration see 
your ICOM dealer. When you mount 
your IC-245/SSB you'll have all you 
need for All Mode Mobile. 



XCUiun 



'j;' r-B 3EL0'-^ C-m-E< 



All, II y>iHic»?J:ni 



4H' IKlrlE'^HHX.a -Tl 




ifllCOM 



ICOM WEST. INC. 

Suite ,? 

1 3256 r^orlhrup Way 
BeJIevue. Wash, 98006 
(206) 747-9020 



Distiibutedby: 



ICOM EAST, INC. 

Suite 307 

3331 TowerwQOd Drive 

Dallas, Texas 75234 

(214)620-2780 



ICOM CANADA 

7087 Victoria Drive 

VivvcouverB-C V:5P 3Y9 

Csnady 

it:.04) 321-1833 



24 Build the Ontni OSCAR i - praptic^ 

O'ri/iitlirectio/Kii aniwifl 

K20VS 
Za Q«1 Sitl For OSCAP 8 - datailson Jfrs 

32 BuHd An OSCAH Zm Trcnivtrutr 

34 PT«diet^n« OSCAR t^opsflSTion - wr 

40 Tfv OSCAR Mobil* - the uftirjtate fJJf 

Iffltf.' 

W2GN 
44 Tic. Tbic ToLichtune — a nmV mBtfiadf 

W9DGI 
SO Visual OSCAR Fkndsf - irrjc» isie ef- 

fmitil 

WB?BWJ 
5J CtiiMp Eat* Fnif OSCAR - m eff^-tivv: 

jaW/j'te antenna 

WflCGI 
£S Track OSCAR WlJi Vour SH-e2 - .-f- 

(?(;^rey rfle PC 100 option 

e2 Try A f-R For OSCAH S - tumnili; 

oyer roflnctOr iysisn 

WflCGL 
64 Trach OSCAR In R?^ TIntti - w,rr^ youF 

HP 67 calculalar 

W91J 
66 Uoglcsl Ttiouglit* Abtfui OSCAR - 

fnesningfut Co cffntputsifi 

qABAD 
72 OSCAR DX - a /reiv dtafleti^s 

W3TM^ 
7G OSCAR Fr«;uBnGy RBiatlonships — 

Ttotv, ivHefb is rny jlciwttink/ 

SO Calculata OSCAR Orbltt - witl} f^ur 

w-^ cmciiiittot 

VE7flGX 
32 CS w OSCAR - from W to (fte *k' 

VJBCGI 
fie Track OSCAR 99 - ^tep-by-smt method 

K22RO 
96 Buitd A 2nit Pothar Amp - gd€iii for 

OSCAR ii^iFifik 

vnAwmt 



98 Build A General Purpose Preamp — uses 
common components! 
W4NVK 
w^ TOO Receive CW With A KIM now, if 

only the FCC . . . 
^j-^ W83GCP, WB8VQD 

Ua 106 Build This SSTV Pattern Generator 
— micro-controlled , of course! 
K7SBK 
US 116 Super Baud Bumper — for your 
SWTP 6800 
WB4GXE 
120 QRZ - P-K4[ - relax with fiam chess 

W9CQD 
1Z2 Digital Timer Goes Mobile - battery 
power keeps it trucking! 
K7QCM 

135 Straining the Wind — simple wind speed 
indicator 

Staff 

136 Find That Meter Resistance — with this 
simple bridge 

N2BG 
144 VE6 DXer Tells All! ^ what to do all 

winter 

VEfiNS 
170 Remote Speaker Mike for Your HT - 

this one's for the Wilson 

W2DNY 
172 Split Your IC-22S - adding splinter 

frequencies 

WA60MH 
174 Remote Monitor for Your Scanner - 

complete with lights 

K1CCK 
176 Electronics Study Guide — remember 

when . . .? 

Wilson 
178 Low Cost Tone Decoder — for repeater 

control 

WB0VSZ 
182 Hufco Counter Kit — report from a 

happy user 

WA2LPB 
184 A Single Tone Can Do It — simple tone 

control system 

W7JSW 
186 Eye On the Weather? — following 

wea ther sa tellites 

WA4WDL 




#206 NOV 1977 



6 
16 
17 
18 
19 
20 
21 
22 
23 
53 
53 
71 
81 
81 
188 
226 



Never Say Die 

Letters 

De WA3ETD 

Contests 

AMSAT 

Looking West 

FCC Math 

Maw Products 

Hamburglar 

FCC 

Oscar Orbits 

RTTY Loop 

Corrections 

Ham Help 

Social Events 

Propagation 



COVER: AO-8. Rendering by R. 
Michael Snnithwick WA6TUF; 
photo courtesy of AIWSAT. 

73 Magazine is published mantbly 
by 73, Inc., Peierborough NH 
03458. Subscription rates in the 
U.S. and Canada arc $15 for one 
year, S26 for two years, and $36 
for three years. Outside the U.S. 
and Canada, write for rates. 
Second class postage paid at 
Peterborough NH 03458 and at 
additional mailing offices. Publi- 
cation No. 700420. Phone: 
603-924-3873. Entire contents 
copyright 1977 by 73, Inc. 
INCLUDE OLD ADDRESS AND 
ZIP CODE WITH ADDRESS 
CHANGE NOTIFICA TION. 



Microfilm edition — Uni- 
versity Microfilms, Ann 
Arbor Ml 48106. 




5TfiFF 






^NAG KG ED.TDR 



.ACim; EDiTOR 



I/O EDITOR 



Miilu„,.| MurpKv 
Wcsilor F,irker 
Dob Sawv*r 



Pfl1t.'[ir>>^ 

PHOTOGRAPHY 

BillHwydQlph 

rciMCiuft 






SH(^P<Kg 

Sue OhjiiiEil^r 



PLAM M^1.M7E:iA\^: = 



ASSOCIjUTEE 

T^, F.n mil I- 1 

Mw • ■• ..ZC2 
**-!■ :■' Vi.A; 7F 

VTWbt Ko;i km II 

BBITjirwrWAAABI 



CCX'PUTeR PROGRAMf; 



ADWEBnSING 




EDITORIAL BYWA YNE GREEN 



MICROCOMPUTING: 
HOW'S IT DOING? 

In addition to the uses of micro- 
computers in amateur radio, I looked 
upon this new field es an opportunity 
for radio amateurs to get into a new 
business which had the prospects of 
growing In an extraordinsrv I'Jay over 
the next few years. It seemed to me 
that amateurs were ideally suited to 
take advantage of this opportunity. 

As a result of the large number of 
articles in 73 during 1975 and 1976, 
an estimated 25,000 amateurs have 
gotten interested in microcomputers 
and become involved with them. 
Quite a few of them have gone on to 
try for the golden ring through manu- 
facturing or distributing micro- 
computers and peripherals. 

Has the field grown as I predicted? 
For once my optimism W3S about 
equal to history instead of ahead of it 
and, yes, it has grown. By way of 
example, the first computer store 
opened in August, 1975. Not only is it 
still going, but by August, 1976, there 
were 50 comptrter stores around the 
country. By August, 1977, there were 
about SOO computer stores and no 
sign of any letup in growth. Have you 
heard of Nashua, New Hampshire? 
Well, there are two stores in that city, 
with £ third getting ready to open! 

What does it take to get into this 
business? If you go about It right . . . 
and I wrote a book on this subject a 
few years ago , . , you can start out 
with very little and build it nuickly. 
You can also start out with a lot (as 
an investment) and let a managing 
firm hire the experienced people for 
you . . . and there already is such a 
firm in the business. Figure On about 
S250,000 if you go the straight invest- 
ment route. 

Perhaps typical of the under- 
finaT>ced system of starting a store is 
the e.xperience of a chap who ^vrote 
me recently. He opened his computer 
Store in a major city with less than 
S10OO in the bank. His sales the 
opening month were S51. The second 
month he sold $B,500 worth of equip- 
rnert and books. The third month 't 
was 814,000 in sales. 527,000 the 
fourth month, and 531,500 the fifth 
month. Sales were slowed down a bit 
due to slow deliveries from many 
manufacturers, plus a growing need 
for cash for expansion. By the sixth 
month, he was ready to open ?. second 
store in the area. 

Growth Is a hltle slower out in tiie 
boondocks, but it is still healthy and 
very forgiving, E\i1ore and more stories 
are corning in from readers of Kilo- 
baud who have walked into one com 



puter store after another with a big 
roll of money in their pocket with the 
intent of buying a computer system 
. . . only to be turned away by the 
utter neglect of the "salespeople." 
The fact is that few stores are run by 
people experienced in marketing and 
sales ... as yet. 

How has it been for people entering 
the manufacturing part of the busi- 
ness? Probably not untypical is the 
firm run by two young ciiaps I know. 
They got i'^terested in microcom- 
puters a couple years ago. but didn't 
have the money to shell out for an 
Altair system ... so they built and 
programmed their own. I visited them 
in early August, 1976, and they had a 
working system which they had put 
together in a workshop in one corner 
of the garage. It looked good to me 
and I suggested that they show it at 
the next computerfest. 

Dealers liked it at the show .and 
placed orders . . . and they are going 
strong today. Not bad for a couple of 
20-year-olds. Their systert really iisd 
the crowds gathered around at Com- 
putermania . . . and every one of the 
television news teains made sure to 
include it on their coverage of the 
show. 

Another youngster is le-year-old ' 
Jeff of Jefftronics. He sells parts and 
small circuits. You'll see him at just 
about every computerfest in the 
country with his booth. 

THEIVIARKET IS 
CHANGING 

Microcomputing is a lot more 
complicated a hobby than amateur 
radio, so it is limited in its appeal. An 
awful lot of people won't spend the 
time and effort necessary to tackle 
this hobby. The result of this has been 
the inevitable dropping off of be- 
ginners in computing. There are a lot 
of new hobbyists, but not the flood 
that came into the hobby last year . . . 
a good part of which were radio 
amateurs responding to the articles in 
73. 

This drop in hobbyists has, as I 
predicted, been taken up by the in- 
creasing interest of businessmen in 
microcomputers as ways to save 
money for their firms. Few computer 
stores now report less than 5Q?i of 
their business going this route and 
many are experiencing up to 90% 
business sales. Ihe hangup on earlier 
sales to business Vt-as the lack of 
suitable programs and dependable 
equipment, fvow that these obstacles 
are being overcome, the increase in 
sales to this market sliould over- 
shadow the hobby market completely. 



There is still a big need for more 
equipment and more programs. My 
prediction is that we will see programs 
being sold in large numbers . . . per- 
haps about the way phonograph re- 
cords and books are sold today. After 
all, once you have a computer, you 
can use it for business, tor games, to 
write music, to generate creative art, 
to study any subject ever known to 
man, etc. There are hundreds of thou- 
sands of programs needed. I think we 
will see sa'es volumes on the order of 
S75 million per day just in programs 
™thin the next ten years . . . and I 
may be very low with that figure. 

THE PIRATES ARE COMIiMG! 
THE PIRATES ARE COIMIMG I 

While I've had a few Ijeefs about 
CBers — in particular the HFer branch 
of the CBers — getting adventurous 
and coming into the ham bands, these 
have all been verbal reports — no one 
has written as yet abotrt it. I'll take 
the problem a little more seriously 
when I have a few vjritten reports on 
the situation in my hand. 

But let's say that it is bound to 
happen, so what can we do about it? 
What have you done or would you do 
if you came up against a bootlegger on 
the air? It isn't that tough on two 
meters, where repeater groups have 
organized their act fairly well and are 
generally able to talk 'he bootlegger 
into getting together for coffee, only 
to have him met by The Fuzz. This 
has helped many a ham get back his 
stolen two meter rig. 

On ten meters, you can easily tell if 
the chap is coming in via ground wave 
or skip. If he's local, it is time to hook 
up a loop ana start hunting, helped by 
some 'other local hams. A personal 
visit by as many of your club mem- 
bafs as you can round up — maybe 
50? — will create an impression that 
should get through to all but the most 
hardened cases. A mass of people can 
be intimidating, even without any 
direct threats of violence. 

What about reporting the miscreant 
to the FCC? Sure, complete witti tape 
recordings, but don't expect much . . . 
if anything. The fact is that most of 
the respcnsibiiity for preserving cur 
bands is in our hands, if we act to 
keep bootleggers out, we may 
succeed. We've seen how powerless 
the FCC is to keep some 100,000 or 
so HFers out of a band, even though 
they have a lis" of most of the p20ple 
involved. 

if you or your club has nad any 
success with discouraging bootleggers, 

Continued on page 183 



m 




WITH DIGITAL mEQUENCY DISPLAY 




Kenwood has done it again? We've combined the fine, time-proven character- 
istic® of the original TS-700A together ^«ith many of the ideas and comments for 
Improvenrtent from amateurs worldwide. Check out the new "built-ins": digital 
readout, receiver pre-amp, VOX, semi-break in, and CW sidetone! Of course, it's still 
all mode, 144-148 MHz anct VFO controlled. 



Features; Digital readoul with 
■ "'Ken wood Blue" digits * high 
gain TBcaivef pre-amp ' 1 ^watt 
low p&wef swj'tlch - buill in VOX • 
sesni-brealt in on CW * CW 
sidetone • Operates afl rnodes; 
:SSB (upper & tower), FM, AM 
and CW * Completely so) id state 
circuitry proviides stable, lorig 
lasting, tioubfe-free opcfatfon * 
AC and DC capability (operate 
frOrtl ydur car, boat. Or Sii a base 
station through its built-in power 
supply) ■ 4 MHz band coverage 
fH4 to 148 MHz} ■ Automali- 
callyswLlches transnil (Teriuencv 
600 KHz For fepeaiei operation. 
Smpiy dial in your cecetvn Fre- 



quency and the radio does the 
rest , simple;<,repealicr. rL^verse 
• Or acicomplish the saine by 
plugging a sincjle crystal mio 
one of Ult' 11 crystal positirins 
fof your favorite cbHrirsel * Trans- 
mit/ Rectfive capab if ity on 44 
channels with I 1 crystats. 

VFO-TOOS 

The perfwt corripsfiion to the TS- 
700S! This fiandsgrmely styled unit 
pmyides you witii extra versaliljly 
and the tuxury of having a second 
VFO in your ihack. 
G'eal tor split frequency operation 
and tor luninrg off IrMniertcv to check 
tPte biinij 



The function switch on the VFO- 
700S selucts the VFO in use and the 
approprLate frequency >s displayed 
on tho digital readout jn Ihe TS- 
"JOOS. If addition, a momentary 
eOfitacl "'ijuquency theck" switch 
aitows vmi IC! Sf)Ol check ihu fre- 
quency of itie VFO nol m use 



TRIO-KEhiyVOOO COMMUNICATIONS INC. 

Till WEST WALNLfT,' COM PTON,CA 90220 




KEIM\A/OOD 




lirovan charactar- 
ftg'inal 
. >^ji-. .ef with 
tany of the idaas and 

r-Lic,-:ii;i.*iOf»« for 
Tiont from 
-vorfdwido 



FUUL COVERAGE TRANSCErVER 

Thij TS-620S (jiavifjes fuN cower- 
fljo on all amateur bands from 
1-8 KJ 39 7 MHi Kenwood gives 
you 160 mstBf capatiilliy, WWV 
on 15.000 MHz , and ar auxil- 
la^i' band |josi(Jon for maxitriLim 
lliexibflily- And wilh the add i [ion 
bf t^B TV-506 transverter. your 
TS-520S can cover 1 60 meters 
to 6 rueters. on SSB and CW 

OlBiTAl. DISPLAY DG 5 (op»iU"i 
Ths Kenwood DG-B provides 
aigsy. accurate readaoi of your 
loperatifig frequency while trans- 
miHmg and receiving 



OUTSTANDING RECEIVER 
SENSITIVITY AND MINIMUM 
CROSS MODULATION 

The TS-520S incorporates a 
3SK35 dual gate MOSFET for 
outstanding cross modulation and 
spurious response characteristics 
The 3SK35 has a low noise 
figure (3.5 dB typ.) and high gain 
(18 d8 typ.) for excellent 
sensitivity 



NEW IMPROVED SPEECH 
PROCESSOR 

An audio compression amplifier 
gives you extra punch in the pile 



ups and when the going gels 
rough. 

VEBNIER TUNING FOR FINAL 
PLATE CONTROL 

A vernier tuning mechanism 
allows easy and accurate adjust- 
ment of the plate control during 
tune-op 

FINAL AMPLIFIER 

The TS-520S is completeiy solid 
state except lof the driver (1 2B- 
Y7A) and the final tubes. Rather 
than subsitute TV sweep tubes as 
final amplifier tubes in a state of 
the art amateur transceiver. 



Kafi worid ■ (la-i onipli>vt;d IwHO 
liusky S-2001A ((NjujvjaluTH !(i 

time-pr(]Ven (ubiii are knnwn for 
theii [o'^n '^^" -!""" ■ ""firh lin«=anlv 



TS-520 



dsi^stniwd bv KfjnwrjuiiJ rhat v" 
feuiltillld iheTS^iOS. 

ThF= TS-620S iiua u buiFi iii 20 
ClB atHfnluHtuT lho[ Laii bu.utli- 
'jfited by 3 pu&^k butiun s.'wich 
canuemsntty LocEilud an thiQ 
ribnl paneJ. 






fictia u'Eii; 



A sp«c>e! Jack on tl^e rear paneh 
of the TS-520S provides isoEjver 
siqrra^ \a en axlernal fBceiver Eor 
insreaseci ^tatHsn versrtility. A 
switch on ths rear panal deter- 
(ninan Ihe signal path . . . the 
regcEusf rn the iS-S20 or any 
exteinaL receiver. 

VFCl ;e2D — MEUV BEMCtTe VF3 
The VFO-520 remote VFO 
fna(cties the stylina of (he TS- 
520S and provriies niajiitrium 
operating (Iexii>i|i1y r>n tlie band 
soJecittd on your 15-5205. 






m. 



e TS-S20S is completely seW- 
conlainad with a rugged AC 
power supply built-in. The addi- 
tion of the DS-IA DC-DC 
converter ^DptionalJ allows for 

bile operfftipn ol the TS-520S 



The TS-520S has 2 conveiniDnf 

flCA phnno ]9c-Ms on she; rear 
panel for PHONE PATCH \H and 
PHONE PATCH OUT. 

ua-J-zi-iu -iI'.V HI_J't>^ |i^F-"TiJN-| 
The CW-520-500 Hz filter can be 
easilly installed and will provide 
improved operatipn on CW 

a, MKtFlS [> TYPE AGT til RCUtV 

The AGC Circuit has 3 posiiions 

(OFF. FAST. SLOW) to enabte 

Hit TS-520S to be operated in 

e optimum condition at all 

irriES whether operating CW 

SSB 



< 



The TS-520S retains aif of the 
features of the onginal TS-520 
that "nade [ tops in its class: RIT 
contra! • 8-pole crystal filter • 
Surit-in 25 KHz calibrator • From 
panel carrier level control ■ Semi- 
break-in CW with sidetone • 
VOX.'PTT/MOX ■ TUNE position 
for low power tune up • Built-in 
speaker • Built-in Cooling Fan • 
Provisions for 4 fixed frequency 
channels • Heater switch. 



Amalet;! E^iids: EB)..! ■ 

M:idE5: !ISa, LJil'. CW 
AnSEnsn.lmf-t'danH: Jii ''i Ul'Uf 
f™qii?'-iv St^sililv; '>ViHliR — I 
'■'i uJiiiig ;;!ii; luui fl^lii tills 
:iliijr.- ji Bsrr.-iiji, rtr.l wihir 

JliOli: durii'i! ■Jii> i-' irim I'' 
l|H'':iJ •liL':i;a'lri 
Tlllrt^.A Si;niciin^iu:liirr- 

[mm. i 1. nofs).'! 

TrilllMtlit-'i P' 

f ETt . L9 

DIud'S 101 

itwct fleii'JiniiPfiii!: iia.tnii 

■K,5fl/W Hi,13.JVUC 

{liiih npimnol DS.)AJ 
ftiWErCnilsuilieWiH- TJaBunil, 

JMWiKt^: SfiMlnf: 26W»t.1* 

(ml^ haaiui oil! 
IiteEiisiBftiS'JtiJ^) W ( 53 (^■0) 

HiiJ35|t3.!lJ-;irTe)ll»Tinfii«|)) 
W«^L J5.* S6{35.2 IhB) 
|l!ik«l£V!inilfi 
RF(iiput.P(j«w:SSB:S(W^fs, 

FFP ew m Walls 01^ 

Cartior SiJflpresMon' 9etlsr Uian 

Sdfiband Siipjircssion Bstter 

lliari -:5D 1^ 
EpuridUS RadiaJiifa: Suiter Ihan 

-40 dS 
Minoilfsne lm(iedsnCK SX OilmS 
.HF R^iC-ansEi 4.311 ;o l.m W 

BfUiyER 

Sensitivity: l).2S irtf (gr Udti 

Setedvit). SSe.Zfl »lt/-« SR 

4.« klHz/-BO dB 
Selettrirly: CW: D.i tiHi/-6 dH. 
■ 1.5 m/-9il iteuiHi jpjiiBiiil 

CW.533 filltr/ 
lunge flaticK Hettti ttaiv M dB 
IF ReJEclicn- BsSfer llian 5D dB 
Af OuipuL PDwe,r: 1 Watt ii 

OIto ImJ, inHlk-tsss Itian IBi 

distorfioft) 
AF Oiilsdl lrfipedartce:+fio;iB; : 
Ohms 

DG-5 

SPECIFICATIONS 
Msasufing Raisje: iOll bjit 

llipul Inioed^ncE 5 fc Qtms 

Sate Tins, u I Sec 

inpus SsnSit.MV !M "U to ^0 

HHi - KO mV iiiii w ore'. 10 

4Hr So ID Ktii . 50 rV nf jvcr 
Measuiin: ftccuf**. NcW lime 

hms ar^raEf ■^<1.\ (ciint 
filwBaa IDMHj 
fljiBfaliKf r«ti|>t:a1jore -lO" In 

M' C/H" iilZ" F 
P«*Er SeniiiieBii^n!; SirypW 

I«am fS'S3)SoiiJ io-lEVDC 

inomittsi P.fl WO 
[Jimensinns: [€?(6 J.'IS W j 

«(!-U/illl H X ?68(]0 S/IS) D 

fflii;(iiiili) 
Weight: 13 kg(2 9 lbs) 




Tnis msiir'-' ■■\ ■•i-i"-?- reanc-. ::; _, .: 
CG'5 -'siii "•• r . Mure ifa^ii jij i . 

'^ifirui** im^t-:s ^iirL cairt€r, UFG. bug *»n,;-.i^.jy-' 
exatA TiaquEn^^y. This handGan>Dl¥'S^''43'i nttUL . 
■ •') yaiir 5hfiiif{ toreaay 'c fisad.r:'. 
iig tnnbile cpeiEiion for fiatatv ■ 
diEjilay v*"' o}»a«tiiiti fse<i>(ency whUe ^r(^ t:- 
with DH (dispStiy ttDldl'SWitcIs for frenti^nayn,.. 
aelactot, TTiB D6^5 cai% also bft ua«d«* P nomtal ffegaar.*:- 
MHz av the Totdch ote sviittsh. {Input naliJe.prtrVideiJ ■ 
NOTE: TS-52D owiRErs san iJse thu DG-o with a OK 



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W« told you ttial iha TS'820 would be 

best. In littls more than a v^ar our 

promise has hscoms g fact. Now. in 

response td hundreds of raqussts from 

amateurs. Kenwood offers thu TS- 

820S' ■ . the same superb tfansceiver, 

hut With the digital readout factory 

irtatall^, As an uwnvr of this beautiful 

fig. you vvill have at your fingertips 

tha oombi nation of controls and feii- 

tur«$ that even under the toughest 

operating condttior>B mako 

I be TSS20S 0>e Pscvsattef ihst it is 



Foltowing are a few of the 
TS-820S many exciting 
features- 

PLL • Ihe TS-820S"enipk>ys 
r!ia Satost phase lock loop 
oiiicuitrv. The single 
Qonverskin receiver section 
performanto ol^fers superb 
protection agmnst unwamed 
c.ioss-modu)ation. And now 
PLL aidoivs the frequency" fo 
remain tire same when 
swjtchiiig sidebands (USB. 
LSB. CWi anil almii nates 
havHTg to recalibrate sacii 
time. 

DIGITAL READOUT ' The 
<tsE}i^l counter dispia^f is em- 
pi oved as an integral pert of 
the VFO readout system. 
Cogiiter mixes the carrier VFO, 
aiiirf first helfifodyne fre-quen-- 
cies to give sxmit frequency. 
Figures the frequency down 
to 10 Hz and digital rJisfsLsy 



read's oui to 100 Hz. Bethi 

receive and Iraiisniit frequeii- 
cies sra ilispiayad m eA?v to 
reas1. K^r Li/;t;K]rl Blue digil^- 
SPEECH PROCESSOR • An 
Rr cfreui! provides (]Uick 
lime constant comprcs^irih 
using a true RF comp''*'^^'' 
as opposed to sr AF clif)par. 
Amount of cornfaresston f5 
adjustable to ihe desired 
iuvftl by a convcnioni front 
panel eonlroL 
IF SHIFT ■ the IF SHIFT 
control vanes the IF pass- 
band Without changing the 
rijceivu frequency Enabitss 
the opefaiQf to aJin>iriatc 
Tinwanled sitjiwis by ntoving 
them out ot the pastjbarid of 
the receiv3r This leatirre 
alone makes the TS 8203 
a pacesetter. 

•The TS-E;20 ana IW-1 arosiril ayolF 
able separahity 




HxpertenEe the excitemertl of 6 

fTKJ.tere-. Th9.TS-600 all mode trans- 
ceiver fets yoLJ experience the fun 
ot 6 meter band openings. 
Tliis 1 watt, solid state rig covers 
50.0-54.0 MHz The VFO tunes the 
sand jn 1 MHz segments. It also 



has provisions for fixed frequency 
operation on NETS or to listen for 
beacons State of the art features 
such as an effective noise blanker 
and the BIT (Receiver Incremental 
Tuning) circuit make the TS-600 
another Kenwood "Pacesetter' 



oo 



-xpertenee the luxury of 450 MHz 
at an economical price. 
TheTR-8300 offers high quaHty 
and sup&rb performance as a result 
of many years of improving VHF/ 
UHF design techniques. The trans- 




ceiveriscapable of Fs emission 
on 23 crystal-controlled channels 
(3 supplied). The transmitter out- 
put is 10 watts. 
The TR-8300 incorporates a 5 
section helical resonator and a 



two-pole crystaf filter in the IF 
section of the receiver for improved 
intermodulation characteristics. 
Receiver sensitivity, spurious 
response, and temperature 
characteristics are excellent 






ITH DIGITAL FREQUENCY DISPLAY 






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m. 














3nl 


VHBiSm 







crx Kia ^ vvcY • na 



^SffSfiS 



«EMO rcH HB- ms tr-ax 








lij' resQout, raoalvar pre-smp. 
' Tit br»«k tn. aiTd CWsidAtonal 
n Biiil all mo({«. 144-148 
MH* and V/FO cantrotlad 



Featur'^: Dit|iial readaui with "Kenwood Blue digils • 
High gain reccwer pre-arnp * 1 watt lower power switch • 
Suilt m VOX ■ Semi-break in on CW * CW sjdetone • 
Operates all modes: SSB (upper 8t lowerj, FM. AM and CW 
' CDmpCelely soltd slat^ cifcuitry provides $tabJe. long last- 
ing, ttDLiblti'-iree operation • AC and DC capability (operate 
Ifom yaut car. lioai, qt as a base station through its Jjuilt-ln 
power supply) • 4 MHz banid coverage (l44to T48 MHz) • 
AutomatJcaHy switches Transmit frequency 600 KHz for 
repeater operation Simply dial in your receive frequency 
and the radio does ihe rest, . . simplex, rupeater reverse ■ Or 
accomplish! the same by plugging a single ccystai into one 
of the 1 T crystal posttions Iw your favorite channel ■ 
Transmif,!'' Receive capability on 44 channels with 11 crystals 




Handsomely styled and a perfect companion to on the VFO-700S selects the VFO in use and 



the TS-700S. This unit provides you with the 
extra versatility and the luxury of having a 
second VFO in your shack. Great for split 
frequency operation and for tuning off fre- 
quency to checi< the band. The function switch 



tlie afjpfopriate frequency ts displayed on the 
digital readout in the TS-700S. In addition a 
momentary contact "frequency check" switch 
allows you to spot check the frequency of the 
VFO not in use. 







11 (MnVT 
r TH-T4CI1CIA 


TCHC 


■liiB 


I14C 


411 



R- 




POWER 

CI ha 



^1 KEN WOOD 

DC POWFH suppLt PS -a. 




JDd s unique Continudus Tone Coded 
Sffueich systenn, 4 MHz band coverdye, 25 watt 
outpul and fully synthssized 800 channeS operation 
This compacT package gives you the: kind of periorin- 
iitice specifications you ve always wanted in a 
2-meter amateur rig. 

Outstanding sensitivity, large-sized hetical resonators 
with Higin Q to minimize unde5>r3b1e out-of-banct 
imerfe ranee, and give a 2-poie 10.7 IVI Hi monolithic 
crysial fiker combine to give your TR-7400A outstand- 
ing receiver performance. Interinadulation characier- 
istics (Better than 66dB), spurious (Better than — 60dB). 
ifnage rejection (Betlei than •70dB), and a versatile 
squelch system malte the TR-7400A tops in itsciass. 

Sliown wili> trro PS'8 iiOWfir supply 

■{Aot.iva fiJtsfs.anid Tone Giirst Modufes optiohafl 



This TOO channef PLL synthesized 146-148 M Hi 
ransceiver comes with 8$ pre-programmed channels 
for use on all standard repeater frequencies (as per 
ABRL Band Plan) and most simplex channeis For 
added flexibility, there are 6 diode-profjrammabie 
switch positions. The 15 KHz shift function makes 
these 6 positions into 1 2"ch^nnefg. 1 watt output, 
-600 KHz offset and LED digital frequency display 
are just a few of the many fine features of the TR-7500. 
The PS-6 is the handsomely styled, matching power 
supply for the Tf? 7500. Its 3.5 amp current capacity 
and built-in speaker make it the perfect companion for 
home use of the TR-7500. 



The high performance portable 2-meter FM 
transceiver 146-148 MHz, 12 channels (6 
supplied), 2 watts or 400 mW RF outp4Jt. 
Everything you need ss included: Ni-Cad 
batter/ pack, charger, carr/ing case 
and microphone. 







Ksniiwimd daw.fllflpfid thfi T 5390 transmtltei and''fl-S9yD 
fBceiver lor the most discrtrninBTing amBUJur 
The R-f599D IS thi; niust Lopripliile receiver t'wtM mfttirfjLl (1 i:= 
entirely aoMd-state, superbly mliahle and compact It covers, rhn 
full amateiir band. 10 through 16Q irTieieffi,eVl/Mi^?S.'iUSE 
AM and FM 

The T-599D is s&fid^tate with the EKKepflonafdinty thrps 
tubes, has bsiilt-in power aypjply invi full rnatQjIng. ll uporijles 
CW, LSB, USB and AM and o\ course, is a perfect match to 
the R-599D receiver 

If YotJ have never considered the advantages of operating a 
receiver./ transmitter combinatior, . , .maybe yo(j should. 
Because of the larger number of controls and dual VrOs Iho 
combination offers flexibility impossible to duplicate with a 
transceiver. 

Compare the specs of the R-599D and the T-599D wilh tuifty 
other brand Remember, the R-599D is all solid ssate (and in- 
cludes four Tillers), Your choice w. M obviously be the Kenwood.. 




Dependabie Ofjeration. siiponcir speCfficatiOfis aind 9X<»llent 

features make ttie R-300 an Unexcelled value for the 

shortwave listener. It ;>ff!:rs fuH band coverage whh a 

frequency raiiyf of I 70 KHz to 30 IVIHz • Receives AM 

SSB and CW • Features large, easy to read drum diais 

with fast smooth dial action • Band spread is calibrated for 

the 10 ftifeign broadcast bands, easily tuned with the use 

of a bui!i-jn 500 KH^ calibrator • Automatic noise limiter ■ 

3-way power supply system (AC/Batteries./External DC) 

. . . take It anyplace • Automatically switches to battery 

power in the event of AC power failure 





Tme equipment that bcbngs in every 
well equipped station 



^ZQ Serms 

T3-K2»S ..TS^aiO with Digital 
kstailed 

1 Q- 1 60 M Deiuxe 
Tranaticiver 

Dig>ia( Frequency Display 
lorlS-820 



"T^-R?0 



>n 



Vi;0-«20 


-Del Mite FftflniMe VFO for 




forrS-320/S20S 


L%V^a20, 


50 iJ Hi CW Filler for 




TS-B2«.»2(}S 


P3-tA 


DC-DC Convener for 




B,20/B30 Series 


520 Series 




TS-b20^ - 


- IHOIf) M Tiansceivei 


DM. . 


Digildl Ffcqijujnty Oisplav 




for TS-52f5 Senes 


v'ejbS2o 


Remote Vro itir TS-520 




Slid TS&20S 


sp^sztt, . 


LxlBFTial SfKiaker for 




F?0/3M Scfies 


C;(iVv62b. 


SOCf Hz CW hdter for 




T£-S2O'S205 


I3K-&2CI. 


Digila! Adaptor Kit for 




TS-520 


599D Series 


R-SaBD. . 


.IfSQ-IOMSQiHl State 




Recalv*^ 


T-SaMD . . 


SO-IOM Matching 




TEnrrsmilter 


^S-6s9 


. External Speaker for 539D 




Sprisji 



CC-29A 2 Meter Converter for 

R 599U 
CC-69 . . 6 Meter Converter for 

H-599D 
FM-599A . FM Filter for R 599D 



R-300 General Coverage SWL Receiver 



TS-600 6 M All Mode Transceiver 

TS-700S . . .2 M All Urtode Digital 

T-ynswjiver 
VFO-TOOS. .Remtise VFO for TS-700S 
SP>70 . Matching Speaker for 

TR-fiOO- 700 Series 
TB-2200A 2 M Portable FM 

Trarisceiver 
rp- 'dOOA 2 M 'Svnthesszecl Deivixe 

FM Trarisceivur 



nl 



Rubber Hcipual Antenna 
Tetescoping Whip Afitunna 
NiCad Bauerv Pacl< isetl 
4 Pin Mii: Coiin(n.-!o? 
Active Filtpr Elements 
Tone Burst Modules 
AC Cables 
DC Cables 



Tfie Kenwood HS-4 hearipfi07ie set adda 
versatrlity to any Kenwood station hor 
extenaed periods of wear Ifie HS 4 is corntort 
ably padded and is compleTe^y adjustable The 
irequency response of the HS-4 is tailored 
spetjifically ^or ^n^^teur communication use 
1300 to 3000 Hz, 8 ohms) 



TR-7500 100 Channel Synthesized 
2 M FM Transceiver 

TR-8300- 70 CM FM Transceiver 
(450 IVIH2) 

TV-506 . . 6 M Transverter for 

520/820/599 Series 



HS-4 . . 


Headphone Set 


MB-IA. 


Mounting Bracket tor 




rR-2 200A 


MC-50. 


i)ssk Microphone 


PS-5 . . . . 


, Power Supply for TR 8300 


PS-6 


Power ??!ippIy for TR7500 


PS-8 , - 


Povi/er Stjppjytor rR-7400A 


VOX-3.. 


VOX for TS 600, 700A 



Trio-Kerwood stocks a corJSfjIeTe |ini> o^ 
replacement oacis. accesSD' ley anct manuals 
for all Kenwood noodeis. 



Mods! = ^a 

RA-1 

T 90-008 2-05 
PB-15 

£07-0403-05 
See Service Manual 
See Service fWanua' 
SpecJfy Model 
Speedy Model 




use w rh 
TR-220OA 
TR 22C0A 
TR-220GA 
AN Models 
TR-7400A 

TS-700A. TFi.7400A 
All Models 
All Models 



The MC-50 dynamic microphone has been 
designed expressly for amateur radio operation 
as a splendid addition to any Kenwood shack. 
Complete witfi P fT and LOCK switches, and 3 
microphone plug for instant hook-up to any 
Kenwood ng Easily converted to high or low 
impedance (600 or 50k ofim) 



TRIO KENWOOD CONIWIUNICATIONS INC. 
1111 WEST WALI^UT/COMPTON.CA 90220 



^KEisiyyooD 



0U ■-'oo: = .i i^ f 


' r K- .' r z rv j: r 


A. '^t " ^^^^^^^^^ 


^^^-Cj^.:t' 


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rEiic 


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lei: Aci h--^il 


I'.-ii 3] e b^h<;u 


1 NEVER SATISFIED 


specific iwo-letier caltsigns enter into 
a game of Russian roulette with the 
Commission. The object of the game 



Two FCC policies, both in con- 
tradiction to FCC rules, have led to a 
gross inequity in the reassignment of 
two-letter W and K callsigns. Rule 
section 97.53 (jl states that, "Callsigns 
which have been unassigned for more 
than one year are normally available 
for reassifinment." 

An existing Commission policy 
does not conform to the spirit or to 
the letter of that rule. The contra- 
dictory policy came to light when an 
amateur requesting a specific two- 
letter callsign previously held by a 
silent key received a "no action" 
response from the Commission. The 
following is an excerpt from 3 letter 
written by Charles A. Kigginbotham, 
Chief, Safety and Special Radio Ser- 
vices Bureau, to the amateur's con- 
gressman. The specific callsign in- 
volved has been deleted as the action 
is currently being reviewed by the 
FCC. In that letter, Mr. Higginbotham 
stated, "Although the amateur station 
license with callsign K--- did expire 
on December 15, 197B, Commission 
procedure is siJch that callsign K- - - 
will not be purged from Commission 
records, and thus bs available for 
reassignment, until some time in the 
future. We purge our records at irreg- 
ular intervals. For this reason, we are 
unable to predict when callsign K- - - 
will become available." That letter 
was written in July, 1977, a full 
eighteen months after the callsign 
holder's license expired. 

That poJicy, in and of itseSf, would 
not be so bad except for another 
Commission policy. That policy, as set 
forth in Mr. Higginbotham's letter, is 
that ". . . we do not 'hold' applica- 
tions in anticipation of the availability 
of callsigns." 

That second policy results in the 
following scenario: An eligible ama- 
teur desires a specific two-letter call- 
sign; he researches the status of the 
callsign and finds that the prior holder 
is deceased or has let his license expire 
and a period of twelve months has 
elapsed; the amateur immediately 
makes application for the specific 
two-letter callsign; the Commission, 
upon receiving the application, returns 
it with a "no action" letter because 
the callsign has not yet been "purged" 
for reassignment. We ail know how 
long it takes from the time an applica- 
tion is sent off until the time a 
response is received. In the interim, a 
less diligent amateur puts in a request 
for the same callsign. By chance, the 
callsign is "purged" the day before the 
second amateur's application is 
reached. An inequity has resulted. 

The result of such Commission 
policies is that amateurs requesting 



is to guess the date the Commission 
records will be "purged" and to time 
one's application for a specific callsign 
so that it will be received immediately 
after the purge. 

One of those two arbitrary Com- 
mission policies must be changed in 
order to result in the equitable assign- 
ment of specific two-letter callsigns. If 
the Commission's policy with respect 
to the purging of its records is 
changed, applicants will know pre- 
cisely when specific callsigns will be- 
come available for assignment. On the 
other hand, if applications are held 
until specific callsigns become avail- 
able, applicants will know that if their 
application for a specific callsign is 
received prior to another application, 
they will be assigned such specific 
cajisign vjhen it becomes available. 

Concerned amateurs are urged to 
write the FCC and demand Jhat these 
policies be changed so that fairness 
exists with respect to the assignment 
of specific two-letter callsigns. 

Kenneth S. Widelitz WA6PPZ 

President 

Persona! Communications 

Foundation 

Los Angeles CA 



TOUGH ONE 



Many thanks for printing my letter 
asking for someone to monitor the 
Novice exam. 1 was able to contact a 
helpful ham and i was successful on 
my first attempt. 

1 might add that the exam was one 
of the hardest I have taken dealing 
with communications. Many of the 
questions do not appear in any of the 
guides I bought. 

F.Cuil!oWA2RQA 
Wassaic NY 



UNCHARACTERISTIC 



1 ma% moved very near to anger and 
rage (very uncharacteristic! by the 
letter of one M. P. Lewton appearing 
in the August issue, favoring the loss 
of part of the 220-225 MHz amateur 
band to the citizen's service. After 
several days, I have calmed suf- 
ficiently to v^rite this letter briefly 
stating my objections to Mr. Lev,rton 
and his three points, as follows: 

1 . H is statement that "we amateu rs 
. . . could operate on the lost fre- 
quencies with our CB license" falsely 
assumes that I either have such a 
license now, or would ever stoop so 
low. 



2. To say that giving up any ama- 
teur frequency Vi/ould be compensated 
for by the availability of cheap radios 
seems to imply that amateurs cannot 
now use those frequencies, but will 
wait for the cast-off and surplus of a 
citizen's band instead of building or 
buying equipment intended for ama- 
teur service. That would be a sad 
commentary on the technical and 
financial state of radio amateurs if it 
were true. Nobody's making any more 
frequency spectrum, and to trade this 
precious resource for a fevj cheap CB 
sets that could be converted would be 
a bad deal for amateurs. 

3. ii/ly ansv/er to "CS really needs 
more room . . ." is to look B! what 
!hey are doing with the frequencies 
they now have. 1 am deeply embar- 
rassed to think that people all over the 
v/orid with shortwave receivers can 
tune across 1 1 meters during an 
opening and form their opinion of 
American mentality and demeanor 
from v/hat they must hear from CB 
operators. If ( had the power, I would 
move all CB operation to a single 
channel at 10 kilohertz, where they 
could share the frequency on a non- 
exclusive basis with Project Sanguine! 

Jerofd R. Johnson WASRON 
Austin TX 



WATCH YOUR STEP 



The Sth Signal Command in 
Worms, Germany, reports that the 
German federal postal and telecom- 
munications department is to begin a 
"crackdown" on illegal CB operation 
by Americans in West Germany. 

Some of the requirements for CB 
How power radiotelephone) operation 
are: 2 Watts input, 500 milliwatts 
output to the antenna, omni- 
directional antenna only: operation on 
channels 4 to 15 only; no connections 
to the public telephone system; and 
you cannot use a mobile as a base. 
Fees are DM S ($2.25) a month for 
mobiles, and DM 15 ($7.75) fof a- 
base. These must be paid on each unit. 
At)solutelv forbidden are: beam an- 
tennas, linear amplifiers, and opara- 
tion outside the federal republic of 
Germany. Also, you can't use your 
ears on the transport routes to and 
from West Berlin. 

Travis Wade, vice-president of the 
Frankfurt area CB club, reports that 
most Americans in that area are so 
afraid of getting a "midnight knock" 
at the door by a German postal 
official that many of these people 
have gone QRT until they think that 
they can operate their illegal rigs 
again. It should be noted here that 
the German Polizei and the American 
MPs do not hesitate to call up the 
American CBers when there is an 
emergency or a lost child, etc. 

American hams here in Germany 
would be vjell advised to carry a copy 
of their license in their car at all times, 
and to remove their equipment v/hen 
their dependents are using their 
vehicles. 

One good thing about operating in 
Germany is that you have a great deal 
of security about having mobile 2 
meter gear. The penalties for auto 



break-in are severe and swift. So is the 
fine for illegal CB operation, some- 
times as high as DM 3,000 ($1,300) 
plus imprisonment. 

Sgt. Charles E. Martin 

WA4YRA/DA1NR 

APO NY 



ACTION 



I finally am getting off my rear to 
write. I have been faithfully reading 
73 since I gave up my membership 
(and sub) to another organization. I 
think you are publishing the best ham 
radio magazine on the market. 

Now, a proposal, strictly food for 
thought. How about a new, com- 
pletely independent amateur radio 
league (call it what you like) — an 
organization trtat would represent its 
membership and not just use their 
money, an organization that thinks 
more of its duties to its members for 
WARC rather than a new building, an 
organization that listens to its mem- 
bers and answers their letters. 1 could 
go on and on, but 1 think you have 
the idea. Can you imagine a head- 
quarters in New Hampshire? Unheard 
of! How about some response from 73 
readers on this? 

Keep up the objectivity of your 
magazine. A iittie controversy is great 
and helps keep the air cleared. Keep 
up the good work and best of luck. 

Chuck Coffee WA6FLV 
Rota, Spain 



ANTJ-RY 



I just received my September issue 
of 73 and am sorry to say I don't like 
it at all; it is ail one-skied for RTTY. I 
have nothing against RTTY, but a 
whole issue of it is too much. 

I have noticed in the past few 
months that you are -specializing on 
one field in each issue. I hope that this 
is not going to be your practice. I 
think the magazine will be a total loss 
Of a bore to other readers who are rsot 
interested in that field. 

One more thing 1 w^uld like to See 
in your magazine is an article on 
amplifiers, especially on 15 and 10 
meters.' They are bad enough on 20m; 
let's hope they keep it there. I want 
everybody to enjoy ham radio, not 
just the ones with high power. 

Donald Laroche WA2FX0 
Syracuse NY 



HOT STUFF 



1 just wanted to send off my kudos 
to Mark Clark WB4CSK for his letter 
(Sept. 1977). I used to be a CBer, but 
I learned and studied and worked at 
the darn thing until I finally started 
getting regular correspondence from 
Uncle Charlie (in the farm of up- 
graded licenses!) almost regularly. 

I'm 14 years old (I got my Novice 
and Tech while 1 was 13) and first got 
my Novice and Tech back in the fail 

Continued on page 48 



16 



De WA3ETD 



John Molnar WA3ETD 
Executive Editor 

SPECIAL ISSUES 

This issue of 73 is dedicated to 
OSCAR usefs, present and future. As 
you probably know, the newest ama- 
teur satellite launching is planneti for 
the first of the year — details are in 
this issue. This bird will feature a UHF 
downlink for the first time, in the 
international amateur satellite band, 
no lessl Many existing Mode B sta- 
tions wli! be able to use their equip- 
ment with no problems. Hopefully, 
the new AMSAT entry will promote 
interest in UHF receiver design and 
techniques! 

Even if you are not interested in 
satellites, the antenna and equipment 
referenced in the OSCAR articles can 
be used for standard VHF/UHF com- 
munications — who knows, the an- 
tenna you've been looking for migfit 
be described in an OSCAR article. 

t have had several complaints about 
the special interest 73 issues this 
summer. Okay, I agree, not everyone 
is interested in RTTY and OSCAR. 
However, the content of the articles is 
applicabSe to all aspects of amateur 
communication. Please don't close 
your mind to new technology — satel- 
lites are becoming more and more 
commonplace in the amateur com- 
munity; future AMSAT shots are 
going to provicie herrjisphere repeater 
operations — think about it! 

At any rate, there are no more 
special issues in the mill right now. All 
suggestions for the same are ap- 
preciated! 

THE COVER 

The cover shot on this issue of 73 is 
an artist's rendition of the new bird — 
it really has not been launched yet! 
Credit to R. Michael Smithwick 
WA6TUF for the cover. 

TAKE COVER 

An article slipped into the RTTY 
issue last month that needed an 
editor's comment. The article^ "RTTY 
Local Loop," is not really perfect for 
beginners. An isolation transformer is 



defirtitely required to isolate the loop 
from the power line! Otherwise, a 
shock could result from contact with 
the loop jacks if the piug is incorrectly 
polarized. In order to be safe, the 
isolation transformer should be in- 
serted between the bridge and the 
power line. Be careful! 

AN APOLOGY 

Due to the extra demands placed 
on the 73 staff by Wayne's Computer- 
mania show, I have fallen behind in 
processing new manuscripts. I am cur- 
rently about two weeks behind — take 
heart, your manuscript is not lost. As 
this is our deadline week, I will make 
a super effort to read all manuscripts 
by next week. Expect to have heard 
from me by the time you read this. 

NEW TRENDS 

Let me know what you think about 
the Gunnplexersand microwave infor- 
mation. If the general readership is 
not especially interested in new 
things, I will cease — however, until 
then, prepare yourselves! The experi- 
ments with the Gunnplexefs are con- 
tinuing; hopefully, in a month I will 
be able to write about the Doppler 
radar system I'm developing. This 
system is based on a counter with a 
modified timebsse that will allow 
direct readout of range, speed, or 
whatever. Again, Computermania cut 
deeply into my free time! 

I obtained a Hughes neon-helium 
laser tube the other day, and am 
attempting to integrate it into some 
kind of experimental communications 
system. So far, a power supply using 
an automotive ignition coil is under 
construction. By the way, ignition 
coils are a good source (cheap) for 
high voltage at low current. A 24-volt 
transformer and variac can be used to 
drive the coil, which is nothing more 
than an autotransformer. It was very 
easy to obtain the 12CX3 volts required 
to fire my laser using such a scheme. 

IWy wife is beginning to wonder 
what's up at our home — between the 
microwaves and now the laser, she's 
thinking about building a copper 



screen around the living area. Be 
careful when playing with these de- 



DEIMOS 

So, you think SSTV is only good 
for transferring QSL cards and pix of 
the shack? This picture is courtesy of 
73 associate editor Dave Ingram 
K'iTWJ. Dave obtained ttie picture 
from the "N6V" gang at the Jet 
Propulsion Laboratory. This picture is 
computer processed, and formerly un- 
reieased. Dave has been doing con- 
siderable work in slow and fast scan 
television with JPL — so without 
additional comment, I'll let the Viking 
News Center (Pasadena CA) tell the 
story: 

"This is a computer-generated color 



picture of Deimos, smaller of the two 
satellites of Mars, A pair of images of 
Deimos from Viking Orbiter 1 — one 
taken through the camera's violet 
filter, the other through the orange 
filter — were combined in this single 
image to search for color differences 
on the surface of Deimos. Resolution 
in this picture shows objects as small 
as 200 meters- Deimos is a uniform 
gray color; slight tints of orange on 
the rims of some craters are artifacts 
of the image process, A small blur 
beside the large crater at the right is 
where scientists removed a reseau 
mark from the original image. The 
reseau marks etched on the imaging 
system are used to make precise 
measurements of the objects in the 
photos." 




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IS Windsor Dr. 
Atco NJ 08004 






Information on all 1978 contests 
should be forwarded as soon as possi- 
ble directly to me f^or oublication. 
Help avoid multiple contests on the 
same weekend with conflicting sched- 
ules by having your dates publisiied as 
early as possible. Also, don't forget to 
send abbreviated results and any 
award information. 

For a slight twist this year, take a 
listen during the OK DX contest. l_est 
year there wa5 good activity from 
Europe even though it was on the 
same weekend as Sweepstakes. 

Anyone interested in a tine news- 
letter for contesters should check the 
National Contest Journal, published 
bi-monthly by the Southern California 
Contest Club, edited by Pete Grillo 
1\!6CJ. Subscription rates are S4/year 
in USA, S5/year elsewhere. F^or more 
information write: NCJ, PO Box 
3762, Glendale CA 91201. 

ARRL SWEEPSTAKES 

CW 

Starts: 2100 GMT Saturday. 

Movember 5 

Ends: 0300 GMT Sunday, 

November 6 

Phone 

Starts: 2100 GMT Saturday, 

November 19 

Ends: 0300 GMT Sunday, 

November 20 

Sweepstakes is sponsored by the 

ARRL. and is open to all amateurs in 

the US, US possessions, and Canada. 

No more than 24 hours of operation 

are permitted during the 30-hour 

contest period. Time spent listening 

counts as operating time and off 

periods may not be less than 15 

minutes. Times on and off as well as 

QSO times must be entered in the iog. 

Eacii station may be worked only 

once, regardless of band. 

CLASSES: 

All entries will be classified as 



either single or '".uitipie operator 
stations. Single operator stations xviil 
be further classified by input powef. 
Obss a = 200 Watts dc or less. Class B 
= above 200 Watts. All ARRL affil- 
iated clubs may also participate in the 
club competition. 
EXCHANGE: 

Number, precedence, your call. CK, 
and ARRL section. Send A for 
precedence if power is 200 Watts dc 
or less, otherv/ise Send B. For Cj^, 
send trie last 2 digits of the year you 
were first licensed. 
SCORING: 

Score 2 points for each completed 
QSO. Final score is sum of QSO 
paints multiplied by the total number 
of ARRL sections plus VES (max. 
751. 
AWARDS: 

Certificates will be awarded lo the 
highest scoring Class A entry and the 
highest scoring Class B entry in each 
section, provided there are at least 3 
single operator entries or the scare is 
10,000 points or more. Certificates 
will also be awarded for high scoring 
Novices and Technicians. Multi- 
operator entries are not eligible for 
certificate awards and will be listed 
separately in the results. 
FORMS: 

It is suggested that contest forms be 
obtained from ARRL, 225 Main St., 
Newington CT 06111. All entries with 
200 or more QSOs must have a 
cross-check sheet to check, for dupli- 
cate OSOs. Each log must show date, 
QSO time, times on/off, exchanges 
sent and received, band and mode. 

Note: These rules were taken from 
Isst year's contest. 

RSGB 7 MHz DX CONTEST 

Phone 

Starts: 1800 Gfl/IT Saturday, 

November 5 

Ends: 1800 GMT Sunday, 

November 6 





Nov 3-4 
Nov 5-6 
Nov 5-6 
Nov 12-13 
Nov 12 13 
Nov 12-13 
Nov 12 13 
Nov 13 
Nov 19-20 
Nov 19-20 
Nov 19-20 
Nov 26 
Nov 26-27* 
Dec 34 
Dec 10-11 
Dec 17-13 



YLRL Anniversary Phone Party 

ARRL Sweepstakes - CW 

RSGB 7 MHz CW Contest 

I PA Contest 

European DX Contest - RTTY 

Missouri QSO Party 

Delaware QSO Party 

OK DX Contest 

ARRL Sweepstakes— Phone 

WWDXA International CVU Contest 

Alf Austrian Contest 

Ten Meter Ground Wave Contest 

CQ WW DX CW Contest 

ARRL 160 Meter Contest 

ARRL 10 Meter Contest 

CW Christmas Party 

^Described it\ last issue. 



EXCHANGE: 

Report and serial number, starting 
with 001. 
SCORING: 

Non-Britisti Isles stations score 5 
points for each contact with the 
British Isles; those outside Europe 
score 50 points. All- may claim a 
bonus of 20 points for each British 
isles numerical prefix worked (G, GC, 
GD, Gl, GM, GW - 2, 3, 4, 5, 6). 
Contacts with stations using GB pre- 
fixes will not count for bonus points. 
AWARDS: 

Non-European stations must mak^ 
at least 10 OSOs to qualify for an 
avjard. 
LOGS: 

Logs and entries must be addressed 
to the HF Contests Committee, c/o J. 
Saaley G3HCT, Brookiands, Ullenhall, 
Solihull, West [Vlidlands, England, to 
arrive no later than December 29. 

MISSOURI QSO PARTY 

Starts: 1800 GMT Saturday, 

November 12 

Ends: 2300 GMT Sunday, 

November 13 

The 13th annual QSO party is 
sponsored by the St. Louis Amateur 
Radio Club in an efforf to activate 
some of the hard-to get h^issouri 
counties. The same station may be 
worked once per band and mode. 
Missouri mobifes will count separately 
from each different county. 
EXCHANGE: 

QSO Number, RS(T), and QTH; 
county for MO stations; state, prov" ■ 
incB, or country for others. MO 
mobiles start with #1 from each 
county activated- 
FREQUENCIES: 

3540, 3910, 7040, 7240, 14040.. 
14270, 21110, 21360, 28110, 28600, 
50-50.5. 
SCORING: 

Score 1 point per QSO; MO stations 
multiply contact points times number 
of states, provinces, and countries; 
others multiply by number of MO 
counties (115 max). MO mobiles total 
separate score Irom each counts/ acti- 
vated. 
AWARDS: 

Certificates to top scores in each 
state, province, country, top 10 MO 
entries, and top 3 MO mobiles. 
ENTRIES: 

iyiailing deadline for logs is Decem- 
ber 15. Address all entries to: St. 
Louis ARC - KSLIR, 842 Tuxedo 
Blvd., Webster Groves MO 63119, 
Include an SAS£ for results. 

DELAWARE QSO PARTY 

Saturday, November 12 

0001 to 0600 and 

1600 to 2200 GMT 

Sunday, i^ovember 13 

0001 to 0600 and 

1600 to 2200 GMT 

Sponsored by the Delaware ARC, 

contest is open to all amateurs. Sta 



tions may be worked once per band/ 
mode for QSO points. 
EXCHANGE: 

QSO number, RS(T), and OTH - 
county for DEL, ARRL section or 
country for others. 
SCORING: 

DEL stations score one point per 
QSO and multiply total by number of 
ARRL sections and countries worked. 
Others score 5 points per DEL QSO 
and multiply by 1 if one DEL county 
is worked, 3 if two counties worked, 
and 5 if all threo counties worked 
(counties = Kent, New Castle, and 
Sussex). 
FREQUENCIES: 

CW - 3560, 7060, 14060, 21060; 
2B160. 

Phone - 3975, 7275, 14325, 
2142B, 28650. 

Novice - 3710, 7120, 21120, 
23160. 
ENTR lESANDAWA RDS: 

Appropriate awards given top 
scorers and a special certificate to all 
stations working ail three Delaware 
counties- Mailing deadline is Dec. 31 
to John R. Lovj K3YHR, 11 Scott- 
field Drive, Newark DE 19713. In- 
clude an SASE for results or W-DEL 
certificate. 

EUROPEAN DX CONTEST 
RTTY 

Starts: 0000 GMT Saturday, 

November 12 

Ends: 2400 GIViT Sunday, 

November 13 

Rules for the contest are the same 
as for the Phone section, with one 
exception: In the RTTY section, con- 
tacts with one's own -continent are 
permitted and count 1 point per QSO. 
Klultipliets will be counted as Ijefore. 

Complete rules appeared in the 
August issue on pafie 22. Briefly, the 
basic rules are as follows: 

Use all bands 3.5 through 28 MHz, 
with only 36 hours of operation out 
of the 48-hour contest period for 
single 'operator stations. The 12-hour 
rest period may be taken in up to 3 
periods. Classes include single oper- 
ator (all band), and multi-operator 
with single transmitter. 
EXCHANGE: 

RST and progressive QSO number 
starting with 001. 
SCORING: 

Each QSO will count 1 point. A 
station may be worked once per band. 
Each OTC (given or received) counts 1 
point — see August issue. The multi- 
plier for non-European stations is the 
number of European countries 
worked on each band. Europeans will 
use the ARRL countries list. In 
addition, each call area in the fol- 
lowing countries will be considered a 
multiplier: JA, PY, VE, VO. VK, 
W/K, ZL, ZS. UA9/UA0. The multi- 
plier on 3.5 MHz may be multiplied 
by 4; the multiplier on 7 MHz may be 
multiplied by 3; the multiplier on 



18 



14/21/23 MHz may be multiplied by 
2. The final score is the total OSO 
points plus QTC points, multiplied by 
the sum total multipliers from all 
bands. 
AWARDS: 

Certificates to highest scorer in 
each country, reasonable score pro- 
vided. Continental leaders wil! be 
honored. Certificates will also be given 
to stations with at least half the score 
of the continental leader. 
LOGS: 

Use a separate log sheet for each 
band. Logs for the RTTY section 
should be mailed no later than Decem- 
ber 1 . North American stations may 
send their contest logs to: H. E. WeiJS 
WA3KWD, 762 Church St., i\fliHers- 
burg PA 17061, USA. Ail others 
sfrould send their logs to: WAEDC - 
Committee, D-895 Kaufbeuren, Post- 
box 262, Germany. 

IFA CONTEST 
Saturday, November 12 
0800 to 1000 and 
1400 to 1700 GMT 
Sunday, November 13 
OSOO to 1000 and 
UOO to 1700 GMT 

Sponsored by the International 
Police Association Radio Club — 
German Section (IPARC), the contest 
is designed to enable participators to 
vi'ork the Sherlock Holmes Award 
(SHA). The contest is open to all 
radio amateurs and SWLs. Members 
may work anyone, non-members may 
oniy work members. General call is 
"CQ I PA." Cross-band and cross-mode 
contacts are not allowed. Ail 
contacts must be on CW or SSB. 
EXCHANGE: 

Non-members send RS(T) and serial 
number. Members send IPA, RS(T), 
and serial number. 
SCORING: 

Every completed QSO counts 2 
points on 80/40 meters, 4 points on 
20/15/10 meters. Stations may be 
worked once per band. Multipfier is 
number of DXCC countries; every 
band counts separately. Final score is 
QSO points times multiplier. 
FREQUENCIES (asallowedj: 

SSB - 3650, 7075, 14295, 21295, 
28650. 

CW - 3575, 7025, 14075, 21075, 
28075. 
AWARDS AND ENTRIES: 

Certificates to winners and three 
highest scores. Any amateur fulfilling 
the conditions of the SHA50, 
SHAIOO, pr SHA200 during the con- 
test may apply with application sheet, 
Approval of 2 licensed hams is not 
necessary for contest application. 
SHA rules, IPARC membership list, 
SHA application sheet, contest log 
sheet, and contest score or certificates 
are available from Vince Gambina 
WB4QJ0, 7606 Kingsbury Road, 
Alexandria VA 22310 - include an 
EASE, please! Contest entries must be 
postmarked no iater than December 
31 and sent to Adoif Vogel DL3SZ, 
Ritter-von-Eyb-Strasse 2, O-8800 
Ansbach, Germany. 

INTERNATIONALOKDX 

CONTEST 

Contest Period; 

0000 to 2400 GMT 



Sunday, November 13 

The participating stations work 
stations of other countries according 
to the official DXCC Countries List. 
Contacts between stations of the same 
country count only as a multiplier, 
but points. All bands from 160 to 
10 meters, CW and phone may be 
used. [OK stations are only licensed to 
operate CW on 160 meters.) Cross- 
band as well as cross-mode contacts 
are not valid. 
EXCHANGE: 

Exchanges consist of a 4 or 5 digit 
number indicating the RS{T) and ITU 
zone. 
SCORING: 

A station may be worked once only 
on each band. A complete exchange 
of codes counts one point, but three 
points for a complete contact with a 
Czechoslovak station (except as noted 
above for stations in the same coun- 
try). The multiplier is the sum of the 
ITU 2ones from ail bands. Final score 
is then the sum total of contact points 
times the multiplier. 
CATEGORIES: 

A — single operator, all bands; 8 — 
single operator, one band; C — multi- 
operator, al[ bands. Any station oper- 
ated by a single person obtaining 
assistance, such as in Iteeping the log, 
monitoring other bands, tuning the 
transmitter, etc., is considered as a 
multi-operator station. Club stations 
may work in category C only. 
AWARDS: 

A performance list of participants 
will be worked out by the contest 
committee for each country. A cer- 
tificate will be awarded tO" the top 
scoring operators in each country and 
each category. The "TOO OK" award 
may be issued to stations for contacts 
with 100 Czechosiovak stations, and 
the "S6S" award (and/or endorse- 
ments for individual bands) may be 
issued to a station for the contacts 
with all continents. Both awards will 
be issued upon a written application 
in the log. No QSL cards are required 
for either sward. 
LOGS: 

A separate log must be kept for 
each band, and must contain date and 
time in GMT, station worked, ex- 
change sent and received, points (0, 1 
or 3), and !TU zone {with the first 
QSO for that zone only). The log 
must contain in its heading the cate- 
gory of the station (A, B, or C), name 
and callsign, address, and band or 
bands. Also, indicate the sum of 
contacts, QSO points, multipliers, and 
the total score of the participating 
station. Each log must be accompa- 
nied by the following declaration; 

/ hereby state that my station was 
operated in accordance with the rules 
of tile contest as well as all regulations 
established for amateur radio in my 
country, and that my report is correct 
and true to the best of my belief 

Logs must ba sent to The Central 
Radio Club, Post Box 69, Prague 1, 
Czechoslovakia — postmarked no later 
than December 31, 1977. A list and 
map of ITU zones is available for 2 
IRCs from the same address. 

WWDXA INTERNATIONAL CW 

CONTEST 

Starts: OOOO GMT Saturday, 



November 19 

Ends: 2400 GMT Sunday, 

November 20 

Sponsored by the Worldwide DX 
Association and DXers Magazine, the 
objective is to contact as many 
amateurs in as many ITU zones and 
countries as possible using all available 
frequencies. All assigned amateur 
radio frequencies from 0. 1 MHa; to 25 
GHz including transponders and re- 
peaters of amateur satellites may be 
used. There are no contest limits; you 
may use complete automation devices. 
Including tape recorders, auto keyers, 
readout devices, or other automatic 
CW devices. You must, however, fol- 
low the rules and regulations gov- 
erning amateur radio in your country. 
Multi-operator, mu Iti-transm itter 
entrants are encouraged. Single oper- 
ator, single transmitter, single band 
entrants must state single category for 
special recognition. All entrants are 
assumed to be multi/multi/muiti un- 
less otherwise stated. The purpose is 
to encourage group contesting to 
enhance teamwork and interaction. 
Shortwave listener entries are a 
separate category. 
EXCHANGE: 

All stations must exchange reports 
and ITU zone numbers. Mobiles 
changing zones during the contest 
period will make changes in report 
sent to show the new zone. Shortwave 
listener logs must reflect zone num- 
bers. 
SCORING: 

3 points for contact on different 
continent, 1 point for contact of 
different country but same continent, 
10 points for contact by satellite 
transponders or repeaters, points for 
your country contact, but multipliers 
count. Multipliers are each ITU zone 
contacted per band and each country 
contacted per band." Final score is 
total QSO points times total multi- 
plier. SWLs score same but on heard 
basis. Land and sea mobiles count as 
different continent (3 points). 
ENTRIES AND AW A RDS: 

Submit your contest summary 
sheet to the contest committee. Do 
not submit your logs — only the 
summary sheet. Include name and 
callsigns of all operators and listeners. 
Contest committee reserves the right 
to request your log to verify your 
entry in the event of close or tie 
scores. Summary sheet must be post- 
marked before January 1; contest 



synopsis will be mailed to each 
entrant before February 15. Trophies, 
prizes, or negotiables are solicited for 
award within country of origin. Re- 
sults of the contest committee are 
final. Mail entries to; Frank Jerome 
W5AT, 908 Holoway, Midwest City 
OK 73110. 

ALL AUSTRIAN CONTEST 
Starts: 1900 GMT 

November 19 

Ends: 0600 GWIT 

November 20 

The contest is open to all amateurs; 
power input must be in accordance 
with licensing regulations. All contacts 
must be on 160 meters, on CW only. 
Foreign stations use the call "CQ 
OE," Austrian stations will use the 
call "CQ TEST." The authorized sub- 
allocations for Austria are; 
1.823-1.838, 1.8E4-1.873, 
1.873-1.900 MHz. 
EXCHANGE: 

RST and QSO number starting with 
001. Each exchange must be con- 
firmed by repeating the exchange 
code. 
SCORING: 

Every completely logged QSO 
(date, time in GMT, frequency in 
MHz, call of station, exchanges given 
and received) counts one point. Multi- 
pliers are 2 points for every Austrian 
"Bundesland" (OE 1-9.), and one 
point for every prefix. IVlultiply QSO 
points times multipliers for final 
■score. Every station can be contacted 
only once. If a station is contacted 
twice, the second QSO must be clearly 
marked as a duplicate and does not 
count. 
ENTRIES: 

Logs must be postmarked no iater 
than December 15 and sent to; 
, Landesverband Salzburg des OVSV, 
"AOEC 1977," c/o Ing. Wolfgang 
Latzenhofer OE2L0L, Pfeifferhof- 
strabe 7, A-5020 Salzburg, Austria. 

^., TEN METER GROUND WAVE 
CONTEST 
November 26 
9 pm to 1 am Local time 
Sponsored by the Breeze Shooters 
of Pennsylvania, send an SASE to 
Richard Evanuik WA3LUIV1, 311 Ever- 
green Ave., Pittsburgh PA 16209, for 
logs and new rules. There will be 
separate categories for Novice/Tech- 
nician classes. 



AMSAT. 



AfVl SAT-OSCAR 7 ORBITAL DATA CALENDAR 



In cooperation with AMSAT, Skip 
Reymann W6PAJ has published an 
improved AMSAT-OSCAR orbital 
data calendar containing all orbits for 
1973 for AiVlSAT-OSCAR 7. Designed 
so that it may be hung on the wall, 
the calendar includes information on 
the operating schedules and frequen- 
cies for the spacecraft, and also the 
telemetry decoding equations. Also 
included is step-by-step information 
on how to determine times of passage 
of the satellite. 



The orbital calendar is available 
postpaid for $5.00 U.S. funds or 30 
RCs (Sa.OOto AMSAT members, and 
free to AMSAT Life Members). Over- 
seas orders will be airmailed. Orders 
and payments should be made in U.S. 
currency to; Skip Reymann W6PAJ, 
P.O. Box 374, San Dimes CA 91773. 

Important — To speed up handling 
of your order, please include a 
gummed, self-addressed label. 

Proceeds from the Orbital Calendar 
benefit AMSAT. 



19 



Looking M/fest 



Bill Pasternak WA6ITF 
24854-C Newhall Ave. 
Newhall CA 91321 

Coordinators, coordinarion coun- 
cils, and concerned spectrum users 
should take note of the following 
date: September 23, 1978. If plans jell 
as it now appears they will, on that 
date the Southern California Repester 
Association, the San Diego Hepeater 
Association, and ihe 220 Club of San 
Diego will cosponsor this nation's first 
VHF/UHF National Voluntarv Coor- 
dination and Band Planning Meeting 
in the city of San Diego, California. 

It has been obvious for a long time 
that coordinators and coordination 
councils all over the nation face 
similar problems and that some 
format has to be found to get all of 
these people under one roof for a day 
or so to giva them a chance to taik 
over their ideas with one another. No 
individual or group had made any 
move toward setting up such a get- 
together. The initiating step took 
place at the August 20, 1977, SCBA 
General Membership Meeting held in 
La Jolla. In his remarks welcoming the 
SCRA to the La Jolla-San Diego area, 
Sam Deer suggested that the SCRA 
schedule its fall, 1978, meeting so that 
it could be held at the 1978 ARRL 
National Convention that he and his 
staff are putting together at this time. 
"Why not make it a national coor- 
dinators meetiny instead?" suggested 
Bob Thornberg WB6JPI, and at that 
moment was born the idea of SCRA 
hosting the first meeting of this kind. 

However, an event of this scope 
would necessitate support from as 
many amateurs as possible, and since 
this will be a seminar held in San 
Diego, it was felt thai the amateur 
community of thai city must be 
directly involved. Therefore, after 
some quick discussions and a few 
letters, it was decided that rather than 
have it be an SCRA-sponsored gather- 
ing, it would be cosponsored by the 
three organizations mentioned above. 

Since plans are still in the formative 
stages, it's liard at this moment to 
describe any program for the meeting 
itself. Orie suggested plan is to hold 
tvvo separate sessions, with technical 
issues discussed in the morning and 
matters of a political nature taken up 
after a good lunch. However, since it 
has been but two weeks since the idea 
itself vjas conceived, exact plans have 
yet to be formulated. In either case, it 
is hoped that this meeting will be 
attended by delegates from all volun- 
tary coordination councils (and/or 
coordinators) here in the United 
States and woddwide, as well as in- 
dividual amateurs who are truly con- 
cerned with overall VHF/UHF volun- 
tary spectrum management. 

Further information on this meet- 
ing will soon appear both here and in 
most other amateur publications. In 
the interim, if you think you might 
want to attend or wish to make 
reservations for a seat (the meeting is 



free, but the sponsors would like to 
know how many people to expect), 
drop a note to the attention of iVlr. 
Paul McClure, Secretary, Southern 
California Repeater Association, PO 
Box 2606, Culver City CA 90230. 
ryiark your envelope "Coordination 
Meeting Info Request," and please 
include an SASE. This meeting may 
mark a historic moment in amateur 
radio's future, so plan to attend. 

CALL FOR PAPERS 

SCRA Chairman Jtm Hendershot 
has informed me that I have been 
"volunteered" by the SCRA to handle 
their involvement in the meeting. One 
idea that I have is to invite you who 
plan on attending to submit formal 
"papers" for consideration and/or 
presentation at the seminar next 
September. In this way, many diver- 
gent opinions and ideas could be 
expressed in a short time on such 
topics as 'The Future of Voluntary 
Spectrum fiflanagement by Amateurs," 
"Coordination Methods for Relay 
Communication," "The Anatomy of a 
Voluntary Coordination Council," 
"User Involvement in Repeater Coor- 
dination," "Advanced Coordination 
Techniques Using Microprocessors," 
"Possibie Voluntary Coordination of 
Non-Relay Spectrum Operations," 
etc. You need not limit yourself to 
the aforementioned list ^ use your 
imagination. Even if you oppose tfie 
concept of voluntary spectrum 
management and feel you have a good 
argument to prove your point, go 
ahead and submit a presentation. 
Since this seems to have been placed 
in my lap anyhow, it is my intention 
to get a "judging committee" put 
together that will be made up of the 
best technica! minds I can muster. 
Those authors whose papers are 
selected will fas invited to present 
them at the meeting. 

I guess that at this point some 
"ground rules" might be in order. 
First, use whatever written format 
you like. It's content, nol Vfl-iting 
form, that's important. Second, it 
should be long enough to present your 
vievi(s in an easy-to-understand 
manner, yet not so overly long as to 
put everyone to sleep. One v^ay to be 
sure is to read it into a tape recorder 
after you have finished it. If it runs no 
longer than, say, 15 minutes and holds 
your interest, tfien you have a poten- 
tial \"/inner. If, after listening for 45 
minutes, you find yourself falling 
asleep, then I suspect that some text 
editing is in order. 

Let's set a submission cutoff date 
of June 15, 1978. This will give the 
committee a chance to read and judge 
all submissions and notify those 
authors selected. However, once you 
find out that you are one of the 
chosen presenters, it's up to you to 
get to the meeting on your own. 
Neittier the SCRA, SAiMDRA, or the 
220 Club of San Diego will be respon- 
sible for providing transportation to 
the meeting, lodging, or any other 



expenses. Costs of such would be 
prohibitive. However, if you are 
one of the "dedicated" ones, you have 
already planned to attend both 
the ARRL National and this meeting, 
so dust off the typewriter and get 
going. Send all submissions to my 
attention, in care of the SCRA PO 
box in Culver City. Also, if you want 
your presentation returned should it 
nol be chosen, please enclose an 
SASE. 

PETE HOOVER ON 

USER INVOLVEMENT IN 

REPEATER COUNCILS 

Herbert "Pete" Hoover III W6ZH is 
probably one of the most respected 
members of this nation's amateur 
community. On August 20, 1977, 
Pete addressed the membership of the 
SCRA on the topic of "User Involve- 
ment in Repeater Councils." Here is a 
partial text of Pete's talk: 

"I've been involved in repeaters at 
one time or another, of one kind or 
another, since I got back from Europe 
in 1964. 1 had control station for one 
of them for a while, first AM and now 
Ffi/I. I'm not a stranger to the mode of 
communication; however, I am not as 
far aside as Stan Brokl is, who wrote 
the comment in here (referring to an 
article that appeared in various local 
radio dub newsletters) saying that the 
two meter repeaters are very close to 
CB activity. I wish they were in some 
respects. 

"A week ago, I was in Dallas talking 
to the REACT International Conven-' 
tion. They have a repeater on 460. I 
think they have a bunch of them. 
They do a good job with them. 
They're commercial users. 

"I would much rather be stuck on 
the road and have to ask REACT for 



help than I would be stuck on the 
road and have to ask the average 
repeater user for help. You might as 
well just forget it. Why? Because 
repeater operators are primarily inter- 
ested in themselves. They are inter- 
ested in commercial communications 
suppliers like themselves {referring to 
repeater owner operators}. They are 
not user-oriented. Otiay, fine, ATV is 
the same sort of tiling, perhaps. But 
there is a problem in the southern 
California region — at least four 
people have mentioned it in different 
terms today: There are no more fre- 
quencies I referring to a'jailable 
southern California tvio meter and 
220 MHir channel pairs} under the 
present situation. 

"And not only that, the communf 
cations service suppliers, the people 
who provide communications services 

— vvhich are you people primarily — 
repeater operators (owners) are be- 
coming increasingly remote for the 
reason that you exist: your users. The 
comment was made here earlier today 

— Is it possible to include a user 
viewpoint in this kind of organiza- 
tion? I'm teiiing you, you'd better! 

"You are, for all intents and pur- 
poses, a communications utility. 
Remember the words — they're going 
to be used more and more. Think 
back on the utilities that you nor- 
mally think about when you hear the 
words. Power company, gas company, 
railroads, airlines, truckers. They 
abused the users of their services to 
the point where the federal govern- 
ment stepped in. And, ladies and 
gentlemen, if the repeater community 
does not get its act together, you are 
going to hear that as a suggestion 

Con tinusd on page 23 




Pete Hoover W6ZH addresses the SCRA at La Jolla. 



20 



FCC Math 



John F. Leahy WB6CKN 
P.O. Box 539 
Gonzales CA 93926 



This is the first in a series for hams 
and would-be harns i^io have trouble 
with math. What we'll do over the 
months is take the equations and 
other math stuff you run into in FCC 
exams srvl handle them in a relaxed 
yet thorough fashion, so that when 
you go to face the friendly execu- 
tioners down at the FCC office, you'll 
be 'jvell prepared to breeze through 
any math curves thrown at you. 

So, if you are a person who can 
handle simple adding, subtracting, 
multiplying, and dividing okay, but 
tend to shrivel up into a quivering 
blob when faced with math that is 
more demanding. This series is for 
you! 

First, let me assure you that if you 
fit into this category, you have plenty 
of company. Recent studies have 
shown that better than half the adults 
in the country can't add. Of course, 
people in electronics tend to be some- 
what more capable along math lines 
than most, but it you're not a 
scientist, engineer, math buff, or 
something, chances are there are areas 
of math where you do not quite feel 
at home, to put it mildly. 

Since the series mill start with 
simple stuff and progress through all 
the math you could possibly need to 
pass any FCC exam (and just about 
anything you might run into in 
popular books and magazines, for that 
matter), you should be able to elim- 
inate areas of difficulty with very 
little trouble, providing, of course, 
tfnt you do what's necessary to let 
the series go to work on you. A good 
quiet nook {not the ham shack, unless 
you're good at resisting temptation), 
far removed from shrieking kids and a 
hysterical XYL, plentifully supplied 
with paper and writing materials, is 
usually helpful- 
No doubt some nf the math of this 
series will be second nature to you. 
There's no reason vjhy you shouldn't 
skip such. A quick glance through 
each bite-sized part as it comes along 
sfjould tell you if tfu's is an area where 
you need some reviev/ or not. Since 
each paa is pretty much self-con- 
tained, skipping certain sections or 
jumping back and forth should intro- 
duce fevj problems. 

One urgent recommendation: If 
you are one of the vast multitude for 
whom math has been, is now, and, 
you fear, ever will be a major catas- 
trophe, RELAX! I roallv msan relax. 
The biggest single obstacle to mastery 
of anything is being uptight about it. 
If you can learn to relax away the 
fears, anxieties, and inner turmoil that 
have built up over the years, you will 
find that there is no area of math you 
cannot completely master, given the 
right approach and sufficient time. 

A good way to relax with math is 
to consider it a game. It you like 



checkers or chess or bridge, you can 
like math. It's just a matter of devel- 
oping the riglit outlook. If you enjoy 
doodling or have ever spent time on 
picture or crossword puzzles, then 
you are indubitably a person v/ho can 
enjoy, yes, take real pleasure in, math. 
And there is this consideration: 
Whereas in bridge or checkers or 
chess, someone has to lose the game if 
someone else wins, in math no one 
need lose. You might be delayed for a 
while, reviewing something you've for- 
gotten, or distracted (that lithesome 
bikinied lass next door), but there's 
no losing unless you choose to lose. 
And you vjill find that solving a math 
problem in electronics is just as satis- 
fying as winning a game of chess, if 
you let it be. In fact, as you progress 
along finding yourself more and more 
successful, you may very well become 
almost as hooked on math (yea, 
verily) as you are on amateur radio. 
But enough of this — let's quit talking 
and start building. 



As I said earlier, we'll work pri- 
marily with the equations you might 
well find in an FCC exam. One of the 
first, which appears in various forms, 
is f - 3OO,OQO,0OO/wavelength, We'll 
daily a bit on this formula so as to 
develop some of the approaches we'll' 
use throughout the series. 

Another way you might see it 
written is ' = cA, where c is the 
symbol ordinarily used for 
300,000,000 metei^ per second, the 
velocity of light, and ^, the Greek 
letter lambda, is the symbol used by 
physicists, engineers, etc., for wave- 
length. 

Before we go any further, let's see 
what different forms this formula can 
be wiggled into. To find out what 
kind of wiggling is legit in electronics 
math, we'll play around with some 
numbers. Take the equation 5 -10/2, 
which might be translated: 5 equals 
10 divided by 2. [Any fraction can be 
considered a division. Divide the 
liottom (denominator) into the top 
(numeratorl] , You'll notice that 5x2 
= 10 and that 10/5 = 2. Well, if math 
is universally valid (let's not get into 
philosophical questions here), then 
using our formula, f = c/^, it must be 
true f X ,\ = c and that c/f = A.. 
(Remember that for purposes of math 
manipulation, letters can be handled 
just as though they were numbers. 1 So 
there are three basic configurations of 
the formula. Which of tfie three 
should be used in a particular case 
depends upon whether you are trying 
to find the frequency or the wave- 
length (presumably you'll never be 
solving for the velocity of light). 

You may have heard, somewhere, 
that light (and other electromagnetic 
waves, including radio) travels 
186,000 miles per second. Of course, 
scientists, in an effort towards uni- 
formity and logic, use meters per 
second rather than miles per second. 
A meter, as you may know, is a lot 



shorter than a mile, in facta thousand 
of them is still less than a mile. To be 
more or less precise, a meter is 39.37 
inches, a little over a yard in length (a 
yard, you will recall, is 3 feet or 36 
inches longi. Now let's take that 
186,000 miles and see If it comes out 
to the 300,000,000 metere of our 
formula. There are 5,280 feet in one 
mite, so there must be 5,280 x 
186,000 = 982,080,000 feet in 
186,000 miles. Anywhere along the 
line you're not quite sure of the 
reasoning, it might be a good idea to 
stop and play around with the ideas 
involved so as to get a clearer picture 
of why we do v^hat v^ do. For 
example, why did I multiply 5,280 x 
186,000 Instead of, say, dividing? Jf 
you're not sure, then you want to 
picture the relative sizes of miles, 
yards, feet, inches, meters, etc., trying 
mentally to fit the smaller into the 
larger, asking yourself how many of 
the smaller fit inside one of the larger, 
drawing pictures representing their 
lengths (trying to draw to scsie, if 
possible) and in general playing with 
drawings and mental pictures until it's 
crystal clear how we go about con- 
verting one unit of measurement into 
another, i^ow take that 982,080,000 
feet, multiply by 12 (because there 
are 12" in one foot), and we have 
1 1,784,960,000, the number of inches 
in 186,000 miies. Now all we have to 
do is divide that number, 
11,784,960,000 inches, by 39.37, the 
number of inches in one meter, and 
we have 299,338,582. So 186,000 
miles works out to 299,338,582 
meters, quite close to the 
300,000,000 of our formula. In fact, 
both 186,000 miles per second and 
300,000,000 meters per second are 
approximations of the value for the 
speed of light. Approximations are all 
we need and, indeed," the best science 
can do. 

A few comments are now in order. 
Notice the large numbers vje were into 
above. Even with a calculator that can 
handle such numbers, errors are easily 
made. Electronics is full of computa- 
tions with numbers larger than those 
we just experienced. Hence shorthand 
methods for handling such numbers 
had to be developed, and you will 
need to learn them If you have not 
already done so. We will cover such 
shonhands in future lessons. 

That 300,000,000, then, is the 
fantastic distance in meters a radio 
wave travels In one second. What, you 
might ask, has that to do with fre- 
quency and wavelengths? (Our 
formula, remember, says that fre- 
quency equals 300,000,000 divided 
by wavelength.) As a matter of fact, 
everything follows logically from the 
meaning of the two words, frequency 
and wavelength. Frequency is the 
number of complete cycles of a 
particular signal that occur in one 
second. Wavelength is the distance a 
wave front travels, zipping along at 
the speed of light, during the time it 
takes the generator of that signal to 
produce one complete cycle. 

If we take an example, we should 
be able to nail this all down. 
Supposing your CW transmitter's 
putting out a signal at 3.625 MHz. 



That's 3,625,000 cycles per second. M 
In MHz stands for mega, you may 
recall, and mega means million. With 
our decimal system the way it is, the 3 
in that 3.625 is the millions and the 
625 is therefore thousands. 

Now we ask ourselves how long it 
would take for one cycle of that 
frequency to he produced. Obviously 
it would be a mighsy short bit of time. 
Well, if there are 3,625,000 cycles in 
one second, then one cycle takes 
1/3,625,000 of a second (just like if 
you travel at 60 miles per hour, one 
mile takes 1/60 of an hour, which just 
happens to be one minute). Again, 
play around with these ideas, taking 
different examples, etc.. if everything 
is not crystal clear to you, iMotice that 
number, 1/3,625,000. It is one over or 
divided by the frequency. So the time 
it takes for one cycle is simply 1 
divided by the frequency seconds 
(providing, of course, that you're deal- 
ing with a frequency expressed in 
cycles per second). This particular 
configuration, 1 divided by the fre- 
quency, is called the period of the 
signal. And physicists use the symbol 
V, the Greek letter nu, in formulas, 
etc., when performing calculations 
that require the use of a signal's 
period. 

Next we ask how far the wave front 
of our signal would travel in that short 
period, 1/3,625,000 sec, because 
whatever that distance is. it is the 
wavelength of our signal. You may 
■ recall distance equals speed times 
time. If I'm going 60 miles per hour, 
and do so for 3 hours, then I've 
traveled 3 x 60 or .180_^miles all told. 
For our radio signal, we multiply 
speed (300,000.000 meters per sec- 
ond) times time or period 
(1/3,525,000 sec.) thusly: 
.300,000,000/1 X 1/3,625,000 = 
300,000,000/3,625,000 which equals 
300,000/3.625. If you're not quite 
sure how we got rid of those last 3 
zeros at the end of each~riijmber, and 
you'll find that you get the same 
answer as you would if you simply 
dropped those last zeros, providing 
you drop the same number of zeros 
from top (dividend, numerator) and 
bottom (divisor, denominator). The 
principle is simple. You're just 
dividing some power of ten (we'll go 
into powers later on) by it^lf, and, as 
you probably realize, whenever you 
divide something by itself, the result 
(quotient) is 1. and I times anything 
is that same anything. So just by 
crossing out the same number of end 
zeros on top and bottom, you've 
carried out a division and gotten rid of 
a hidden 1 1 

Before we find what 300,000/3,625 
equals, you might notice that 3625 is 
our original frequency, but as it would 
look expressed in kilohenz (kHz). In 
other words, 3.625 MHz equals 3625 
kHz (equals 3,625,000 Hz or cycles 
per second). We'll get back to this in a 
later lesson, and show how to use our 
formula, f = 300,000,000/wavelength, 
with megahertz, kilohertz, or Hertz 
(as we are in this lesson) without 
converting the megahertz or kilohertz 
into Hertz. 

Continued on page 23 



21 



Nen^ Products 



OPTOELECTRONICS FC-50 

FREQUENCY COUNTER 

IMPRESSIONS 

Considering myself a confirmed 
UHF/VHF entliusiasi, 1 was pleased to 
review a !ie\'J frequency counter useful 
in the UMF spectrum. My present 
counter is a horrLe brew 50 MHz job 
construcied on perfboard, with a pre- 
scaier that starts to gasp at 450 MHz. 
Thus, the new Optoelectronics FC-&0 
counter with 600 WT prescaler could 
not have come along at a better time! 

Optoelectronics is best known for 
their clock kits and electronic com- 
ponents. I was surorisfid to discover 
that they also offer a quality counter, 
available in kit and pre-built form. 
The basic counter is the model FC-50, 
which will respond in the rarjge of 10 
Hz to about 65 MHz. I evaluated a 
factory-built niodel, although instruc- 
tions for the kit builder were pro- 
vided. The user instructions provided 
with the kit assume some knowledge 
of components and mounting tech- 
niques; even so, they are easy to 
follow, and are complementec with 
several pictorial diagrams. 

The FC-50 requires five volts for 
operation; thus, it can be used in the 
field with battery power and a 309 
regulator. The eight digit LED display 
features leading zero suppression, 
which means that only the significant 
digits ol the frequency being moni 
lored will be displayed. The sup 
pressed display is controlled by a 
front panel toggle switch. The LED 
display fBa'ures A" digits for easy 
reading. In addition to the leading 
digit suppress switch, front panel 
controls consist of a power switch, 
gate time control, and a prescale 
switch to enable the optional 650 
MHz prescaler. The gate time control 
is a two-position switch which allows 
either a one second or 1/10 second 
sample time. In effect, this allows the 
display to be updated on either of the 
time intervals. A BNC connector is 
provided for rf injection. 

The FC-SO counter has a claimed 
accuracy of 1 ppm (:^.0001%). 
Stability after 25 minutes is also 1 
ppm. Input sensitivity to 50 MHz is 
10 mV rms, and impedance is 1 
megohm with a load of 20 pF. If the 
600 WT prescaler is used, the input 
reouirements increase to about 150 
mV rms. 

Using the counter is a snepi 1 
plugged my unit in and allowed a 
warm-up period of 10 minutes. My rf 
probe consisted of a three-inch clip 
lead twisted into a turn coil. This coil 
was attached to a short piece of coax 
which terminated in a BNC connector. 
I had a 2m Wilson HT nearby, which 
provided an easy test. Presto - . . tile 
HT provided an accurals count at 
distances up to five feet from the 
counter! I: vjas an easy job to cali- 
brate my HT . . . sure enough, several 
channels were off frec]uency. Mo 
worxler I couldn't hit one of the 
"local" machines! 

The real test came with the 450 



MHz HT. This rig provides only 500 
mW of output, and was originally 
calibrated by the old "tweak until you 
access the machine" method. Amazing 
— the counter immediately indicated 
the frequency, and, as it turned out, I 
was close. Without wasting any time, I 
checked my entire UHF setup, using 
the simple coil pickup in all cases. 

In my opinion, the Optoelectronics 
FC-50 counter and 650 MHz prescaler 
are hard to beat for the price. The 
eight digit display makes accurate 
UHF counting possible, and the accu- 
racy is definitely OK for amateur use. 
Housed in a 6" x 6" x 3" plastic box, 
the counter is attractive ar'.d portabia 
The most amazing thing about the 
FC-50, however is the price. The 
basic 65 .VlHz unit in kit form is 
available for $119.95, complete- 
Factory wired, the unit costs $165.95. 
The prescaler kit is available for 
$29,95, and mounts inside the FC-50 
case. This option is controlled by the 
front panel prescale switch. Sockets 
are provided for all IC packages, and 
quality components are in evidence 
throughout the counter. Optoelec- 
tronics, Inc., Box 219, Hollywood FL 
33022, 

JohnMolnarWASETD 
Executive Editor 

YAESU INTRODUCES 
THE IWEIMORI2ER 

A solid state, fully synthesized 800 
channel 144-148 MHz two meter FM 
transceiver. Model FT-227R, featuring 
a photo optic sensor, has been an- 
nounced by Yaesu Electronics Corpor- 
ation of Paramount, California. This 
new Yaesu product has a memory 
circuit to put you on any preset 
channel with a flip of tiie memory 
switch, and has been designated the 
Yaesu "Memorizer." 

Frequency readout is by means of 
four large LEDs. Optical sensing elimi- 
nates switch problems in frequency 
selection. PLL techniques are used for 
fully synthesized frequency controi in 
5 kVii steps, and a special memory 
circuit allows instant return to any 
preselected frequency within the two 
meter band. Plus or minus 600 kHz 
offsets, plus any odd split within the 
two meter band, can be achieved using 
the memory circuit- 

The new FT-227R has automatic 
final protection, PLL unlock protec- 
tion, and a busy channel indicator. It 
provides built-in tone burst, plus op- 
tional tone squelch-decoder, and selec- 
table ten Watt or one Watt output. It 
exceeds the latest FCC requirements 
with spuries well below the minus 60 
dB down requirement with superior 
cross modulation, overload, and image 
rejection. Compact {ISO mm x 60 mm 
X 220 mm), lightyjeight (2.7 kg. I, the 
FT-227R requires 800 mA on receive 
and 2.5 Amps on transmit at 13. S V 
dc plus or minus ten percent. And, 
best of all, it is priced at under S300I 
The Yaesu FT-227R is scheduled for 
iate September delivery to all 
authorized Yaesu dealers. Yaesu Elec- 




Intsgral's Model 42 current tracing meter. 



tronics Corporetion, 15954 Downey 
Ave., P.O. Box 49S, Paramount CA 
30723, (213) 633-4007. 

WIRE-WRAPPING 
WIRE 
The finest industrial quality AWG 
30 (0,25 mm) wire-wrapping wire is 
now available on compact, convenient 
50' {15m) rolls. Perfect for small 
production applications, prototype 
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the wire is silver-plated OFl-iC copper 
with Kynar insulation. This premium ' 
insulation combines excellent elec- 
trical and mechanical characteristics 
with easy stripability and is available 
in 1 colors (red, white, blue, and 
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po ration, 34b5 Conner Street, Bronx 
NY 10475. 

CURRENT TRACING METER 
INTRODUCED BY 
INTEGRAL ELECTRONICS " "" 
CORPORATION 
A current tracing meter, 
MICROPROBER Model 42, recently 
introduced by Integral Electronics 
Corporation, is specifically intended 
for isolating defective ICs on as- 
sembled printed circuit boards. The 
new instrument is especially useful in 
the troubleshooting of bus-oriented 
circuitry, such as encountered in 



microprocessor assemblies. Detection 
of random solder shons on printed 
circuit boards and location of extra- 
neous wires in back planes and wire- 
wrap assemblies are greatly simplified 
with the aid of this device. The 
sensitivity of the current tracer, 
spanning a 10,000:1 range, permits 
equally effective fault isolation of 
TTL, DTL, CMOS, and ECL circuits. 
The instrument is portable and 
powered by a single 9-voit battery, 
providing up to 300 hours of con- 
tinuous operation. 

Available from stock to 45 days at 
S94.50 each. For further information, 
contact Marcy Talbot, Sales Manager, 
Integral Electronics Gorporation, P.O. 
Hox 286, Commack NY 11725, tele- 
phone (516) 269-9207. 

NEW TWO-WAY 
TEST SET liMCLUDES 
COMPLIMENTARY 
CARRYING CASE 
A Thruline® direcftdnal RF watt- 
meter and a Bird 100 W dry load 
constitute the core of the new mode! 
4300-064 test set. Selected especially 
for convenience in servicing mobile 
communications equioment. acces- 
sories include an rf sampler v^ith 
variable level control for signal fre- 
quen.cy, spectrum and envelope 
analysis, two UHF connectors, two N 
connectors (on the Model 43 watt- 

Continijed on page 1S8 




The "Memorizer" from Yaesu Electronics Corporation. 



22 



Looking W<2s\ 



from page 20 

more and more ofter. And who from? 
Your users. And liow rnany users are 
there versus how many suppliers? 
Repeater operators (ovjners): You 
don't stand a chance. 

"Okay, vjhat's the answer? You 
can't do it by legislation. It has lo bs 
done in a voluntary manner. No tvvo 
ways about it. You havs to have an 
end objecTii/e, and your end objective 
must be to make better use of the one 
resource you have, the spectrum. You 
havs to relate what you are doing to 
the users of your service. You have to 
ally yourselves as repeater operators 
fawners) with the organizations that 
your users belong to — Red Cross, 
Salvation Arrr;y, ARES, RACES. Sure, 
RACES is part of the repeater oper- 
ators group. I can thmk of tv/o 
RACES repeaters That in times of 
disasters turn themselves off! 

"Suggestion [it's been made before, 
but please give it some serious 
thought): You've got some very com- 
petent people here. Consider, over a 
period of two years, phasing in sorr^e- 
thing like the following, which is 
modeled primarily after the commer- 
cial FM broadcast practice. You have 
class A, S, and C stations, from very 
low power local machines (and this is 
akin to JR's comment about it being 



installed in someojie's sub-baseme.n£, 
running a half a Watt to a wet noodle) 
to the 'clear channel stations' (wide 
coverage), maybe like a .34/. 94 on IWt. 
Wiison. Who knows? Chances are ex- 
cellent that if you approach it from 
the same allocations viewpoint that 
the FCC has in the past used for 
allocation of FM frequencies {com- 
mercial ones for broadcast), you can 
increase the number of repeaters on 
the air by three- or fourfold without 
increasing your spectrum. But you are 
going to have to instill in your 
members a discipline that currently 
does not exist. It will have to be done 
by cooperation. This is probably going 
to require an alliance with users, and I 
am delighted to see soineorw from 
northern California here (referring to 
i\IARC Ciiairman Dave MieTti), 'cause 
that's where it begins. 

"As a start, the only repeater that I 
am presently a user of is the ANY 
repeater in Pasadena. Talking to the 
people on that repeater, 1 understand 
that there is a potential conflict with 
AQD here in the Claremont area of 
San Diego. We are willing in Pasadena 
to reduce our ERP to 1 Watt- That 
will give us the possibility of covering 
the San Gabriel Valley and a portion 
of Los Angeles. We challenge AQD to 
do the same thing. This kind of thing, 
I think, will lead to a lot fewer 



headaches for your technical com- 
mittees, and probably will give you a 
better system all around. That and 
aligning yourself with the Red Cross 
or any other communications user. 
Remember, you are only in business 
because your users let you stay in 
business. The moment they tire of 
you, there goes your toy. No longer 
can you put these things (repeaters) 
on the air for your own personal 
amusement — which is what most 
repeaters are on the air for, I'm sorry 
(to say). 

"That's the end of my general 
comments; I was delighted to see 
SCRA members at the L.A. Council of 
Radio Clubs meeting. To my knowl- 
edge, that's the first they had ever 
attended a meeting. I hope it occurs 
more often. Okay, enough of the 
lecture; any questions?" 

This was transcribed directly from 
tape recordings made at the time and, 
with the exception of the deletion of 
his opening remarks pertaining to 
WARC '79, is presented totally un- 
edited. Comments on the foregoing 
can be made either directly to Mr. 
Hoover or to him through this 
column. 

THE BIG FIRE 
By now, most of you are aware of 
the fact that this summer California 
suffered some of the worst wide-area 
fires in the state's history. They 
seemed to spring forth without warn- 
ing to consume hundreds of thousands 
of acres of valuable land. In the case 



of the big Santa Barbara fire, 
hundreds were left homeless in the 
fire's wake. 

I have received many reports of 
how amateur radio - both HF and 
VHF — iias been working at the front 
lines to provide the necessary com- 
munication when called upon to do 
so. As 1 write this, the giant Marble 
Cone fire has just been "contained," 
and the weary firefighters are into 
their final "control" phase of the 
fight. It still will be many days before 
it's out. 

Two peopie who have supplied 
information for us are Bob Couger 
VV6KPS, who lives up near the Santa 
Maria area, and Sob Jensen W6VGQ, 
who was up in the fire area with a film 
crew. Their information, along with 
input derived from a report given to 
the SCRA by Southwestern Division 
Director John Griggs W6KW, makeup 
tlie background for what you are 
about to read. 

The most important aspect of ama^ 
teur radio's involvement in the fire- 
fighting efforts was that amateurs 
arrived "ready to set up communica- 
tions" — but were not pushy about it. 
They simfjfy let those in charge of the 
overall effort know of their avail- 
ability, and then waited to be asked to 
participate. They did not have to wait 
very long for the call. The fire being in 
the type of terrain it was, very little 
land-based communication already 
existed — and what there was in the 

Continued on page 27 



FCC Math 



from pags 2f 

N-ow back to that 300.000/3,625. 
Dividing out, we get 82,8. the length 
of one wavelength of our 3.625 iVlHz 
signal in meters. I leave to the reader 
the exercise of converting 82.8 meters 
to feet. Just remember there are 39.37 
inches in a meter. The answer is 
below.' You may have noticed that 
did not carry the division above out 
beyond one decimal point. The reason 
is simple. There's no reason to be 
more accurate than that here. Yo'j get 
a feel for proper degree of accuracy as 
you increasingly bump into reality. 

Finafly. let's tie everything together 
so VJe can see what we've done and 
where we've been. We started, you 
recall, with the formula f - 
300.000,000/ waveiength, which, with 
further symboiism. is ' = cA. This can 
be tortured into the two variant 
forms: f x X - c for simply fX - c; 
multiplication sign need not be writ- 
ten between two letters, and two 
letters next to each other are under- 
stood to be a multiplication! and c/f = 
A. Then we took our elementary- 
school formula, distance = speed times 



"271.7 feet. Wc multiply S2.8 hy 39.37 to 
get 3259.8, the niJiT\ber of Inches in 82.S 
^eterj. Then divide by 12, getting ojr 
ansv^er. 



time, and applied it to our case, 
getting wavelength = 300,000,000 
times period. And since period is 7 
over frequency, we derived, reslly, iIig 
formula, wavelength = 3O0,O00.00O/f 
or X - c/f, which, as you car see, is 
the second variant above, only written 
with the symbols interchanged from 
one side of the equal sign to the other 
(after all, it doesn't make much differ 
ence whether you say 2+2 = 4 or 4- 
2-^2, does it?). So really, you don't 
need to remember the formula: fre 
quency = 300,000,000/wavelength. 
All you need is distance equals speed 
times time, remembering that in our 
case distance is vjavelength, speed is 
300,000,000 meters .oer second, and 
time is 1 over frequency. And if you 
can't remember what variants the 
formula can take, go back to a simple 
problem, e.g., 2 x 3 = 5, so S/2 = 3 
and 5/3 = 2, but notice that 6x3 
does not equal 2, nor 6 x 2, 3. nor 
does 3 T (divided by) 2 = 6. etc. Only 
variations that work with numbers 
will work with letters. So, fc t= X (y 
means "does not equal"), f/c "f^ X,etc. 

Now, with all this logic and all 
these tricks under your belt (if you'll 
pardon the mixed metaphor), here are 
a couple far you to work out. Check 
yourself against the answers (and 
work) below. 

1. What is the free space wave- 



length of a 146.94 MH? signal (meters 
and feet)? 

2. What is the frequency of a signal 
whose free space .wavelength is 5 
inches? 



Answers 

1. V.'e use the Sonruls iV = c'f. The 146.94 

MHz is 145.940.000 cycles per second. So 

we have: 300,000,OOQ;i46,940,DOO' "= ' 

30.000/14.694 = 2.04 meters. Multiply 2.04 

X 39.37 anc: we have 80_31 iiich&s. Divide t:y 

1 2 and \ve have 6.69 feet. 

2- Here v;e are lookirrg for frequency, so vjs 

use the fornnula f - c'X. Our formula 

requires meters, remember, rather than 

ini^hes. So v/e must first convert S inches 



into meters. Since there are 39.37 inches in 
one meter', we :ire lleie denling wjth a lot less 
than one meter. In fact we are dealing with 
5/39.37 of a meter. Divide tlial out and we 
-have 0.12? meters. Slipping that into the 
formula, we have f - 300.000,000/0.127 = 
2,362.204, ODD, Again, we need not carry the 
division all the way out. Jjst put in the 
correct nL]mt>Gr of zeros after -working it out 
a reasojiaijle arriouni, so as to get us into the 
right iTiMjni-.urle. 2,362,204,000 a/Aei per 
second is 2362. 20rl HHj. vjhich is our 
answer This matter of how far ro work a 
problriT oul Is not terribly imporranT for 
our purposes, since FCC exams are multiple 
choice and tjrM:e you have the first couple of 
digits and know the size of the ansvjer 
(whether hundreds, millions, or \vhatever), 
you can easily select the correct ans-A'er. 



Tracking 

the Hamburglar 



STOLEN: Collins KW^': 2. s.'n 11023, 
Johnson Viking 250 Watt matchbox, 
Swr bridge, Eico tube checker, electro 
voice dynamic rr:obile mike, volt ohm- 
meter, and all my old 73 magazines 
starting from the first issue through 
about 1969. Contact Richard M. 
Olson, 5123 Mezzanine Way, Long 
Beach CA 90808. 

PURLOINED: Heath HW2Q2 with GE 
mic and BNC ant. conn, on back. 
WB8TDW, Ohio lie. No. NA22S8S3, 
and SS No. 232-72-8842 marked in 
metal of case. Rig was removed from 



ear in Las Vegas. Nevada. Contact 
Chuck Young W38TDW/7. 2165 £. 
Rochelle =79, Las Vegas NV 89109, 
(702) 733-8243. 

SHANGHAIED: Heath Model 2021 
handie-talkie with Model 201 touch- 
tone pad built-in. Channel switch 
wired wrong in that channels 3, 4, and 
5 go to crystal sockets 3, 2, and 1. 
Crystalled for 146.52 (ch. 3), 146.655 
(ch. 4), and 146.94 (ch. 5). Stolen 
July 23, 1977 in Westport CT. S. W. 
Daskam KIPOK, 38 Settlers Trail, 
Stamford CT 06903, (203) 329-0137. 



23 



Build the 
Omni-OSCAR! 



- practical omnidirectional antenna 



iay Buscemi K20VS 

S Wexford Ct. 

St. James NY 13 780 



Due to the extremely 
good sensitivity of the 
receiver on IVIode B, OSCAR 
1, extensive antenna arrays 
with high gain for the 432 
MHz upiinl< are hardly re- 
quired. In fact, excessive erp 
due to the use of high gain 
arrays by ground stations has 
been a problem for some 
time. High uplink erp causes 
the age on board OSCAR 7 to 



desensitize the receiver, thus 
preventing weaker stations 
from accessing the satellite. 
Also, the batteries may be 
excessively drained by the 
high current demand, 
shortening their life. 

Therefore, simple low gain 
antennas with omnidirec- 
tional characteristics are 
appropriate for use on this 
mode. 50-70 Walts of rf into 
a unity gain antenna will fully 
access OSCAR 7 for all but 
the most marginal conditions. 
The use of an omnidirectional 
uplink antenna is a tre- 
mendous advantage during a 
satellite pass, as it eliminates 
the need to track the satellite 



in azimuth with a directional 
array. In addition, certain of 
the antenna designs described 
here also provide good over- 
head coverage. Gain arrays 
perform poorly at high eleva- 
tion angles unless an elevation 
rotator is also provided for 
the antenna. 

All the antenna types 
described here may be con- 



structed for either two meters 
or 432 MHz. Dimensions for 
both bands are given in Table 
1 and refer to the dimensions 
designated by A, B, C, etc. in 
the figures. 

Quarter Wave Monopole 

The simplest omnidirec- 
tional antenna is called the 
quarter wave monopole (also 
called the vertical groimd 
plane), which consists of a 
single vertical element, one- 
quarter of a wavelength long, 
mounted over a ground plane 
of at least one-half wave- 
length on a side (Fig. 1). This 
antenna produces a doughnut 
shaped pattern with a null 
directly overhead and the 
pattern falling to zero at the 
horizon. Obviously, the omni- 
directional term as applied to 
this antenna is only mean- 
ingful in the azimuth plane, 
its elevation plane pattern is 
symmetrical but certainly not 
omnidirectional. This antenna 
becomes quite ineffective at 
elevation angles greater than 
40 degrees from the horizon, 
making it almost useless on 
satellite orbits jvhich pass 
close (up to 300 miles) to the 
ground station. Still, its 
simplicity makes it useful for 
-some applications. 

Construction of the mono- 
pole is nearly trivial — mount 



COrjSriiUCTION- 




ALUMINljM OR 
COPPER SHEET 



COAX TO TRANSMITTER 



iZIf^UT^ PATTEfff/ 




Turnstile over ground plane (432 MHz). 




ELEV^TfOM PATTEPN 



PQLARtZATWtJ- 




DOJSHNUT' SHAPED 



/ 



Fig. ]. Quarter wave monopole. 



24 





/ 



Sloped turnstile over ground plane (432 MHz). 



Top view. Sloped turnstile overground plane. 



a panel-mount BNC or N con- 
nector in the center of an 
aluminum or copper sheet 
and solder a quarter wave 
long piece of #8 or #10 bus 
wire to the center pin. The 
vswr should not exceed 1 iS 
to 1 without further match- 
ing. Trimming the length of 
the wire will permit a closer 
match, if desired. 

Dipole Over a Ground Plane 
(Fig. 2) 

Another simple antenna 
which works well on over- 
head passes of the satellites is 
the half wave dipole over a 
ground plane. This antenna 
provides some gain (1 .5-2 dB) 
overhead, but has nulls off its 
ends and near the horizon. 
Like the simple quarter wave 
monopoie, it is linearly 
poSarized (horizontal), so 
fading due to rotation of the 
satellite with respect to a 
ground station is still present. 
ManuaS switching between a 
vertical and horizontal 
antenna can be done during 
satellite passes to pick the. 
best polarization at any given 
time. 

In order to minimize the 
effect of the nulls off the 
ends of the dipole, this 
antenna should be oriented so 
it favors NNW-SSE (in the 
continental US}, as most 
ascending node passes go out 
to the NNW during the eve- 
ning, local time. 

No balun is required. The 



antenna pattern may be 
slightly skewed, but no real 
advantage is gained by 
feeding the antenna in a 
balanced mode. Purists can 
add a quarter wave de- 
coupling sleeve over the 
upright feedline. 

As with the quarter wave 
vertical, the vswr as con- 
structed will generally not 
exceed 1 .5 to 1 , and the 
dipole element lengths may 
be trimmed to achieve a 
perfect match. The spacing of 
the dipole off the ground 
plane has been chosen for 



CONSTRUCTIOfJ- 



best omnidirectional coverage 
in the elevation plane. Some 
gain can be achieved by vary- 
ing this spacing at the 
expense of pattern symmetry. 
The dipole elements are 
constructed from 1/8" 
diameter copper or aluminum 
tubing, flattened at the" end 
and fastened to a plastic or 
printed circuit board disc 
with #4 screws. The feedline 
(and vertical support] is made 
from a length of semirigid 
coaxial cable (RG-405 or„ 
equivalent) which is soldered 
to a coaxial connector 



mounted on the ground 
plane. Do not ground the 
coax connector to the ground 
plane — it should be mounted 
on insulated spacers. Cut a 
clearance hole in the ground 
plane to provide connector 
access from the bottom. 

Turnstile Over Ground Plane 

A worthwhile improve- 
ment over the simple dipole 
may be had by adding an 
additional dipole fed 90 
degrees out of phase to the 
simple dipoie described 
above. This provides two 



D ETA ft X 




RIGID COAX 




CLEARANCE HOLE 
IN GROJNn PLANE 



ELEVATION PATTERN 

SMALL DIP OVERHEAD 



AZimUTH PATTERN 




RIGID 
ELEMENTS- \ COAX 

FLATTEN ENDS S 
DRILL 1/8 in DtA, 



N0.4 SCREWS 8 
SOLDER LUGS 



1/2 -2]n PLASTIC DISC 





POi-Af^lZ^TION- 






HORIJONTAL 






/ 














HORIiONT^L 


LIN 


:ar 



Fig. 2. Dipole over ground plane. 



25 



advantages: the antenna will 
be circularly polarized over- 
head, and ihe nulls off the 
ends of the simple dipole are 
eliminated, providing a more 
uniform azimuth pattern. 

This antenna, commonly 
called a turnstile, has been 
extensively used for HF and 
VHF ground communica- 
tions, but its major advantage 
is in satellite communications 
— circular polarization over- 
head is not a factor in ground 
communications use. Circular 



polarization minimizes polari- 
zation fading overhead when 
the satellite tumbles or 
rotates. Near the horizons, 
this advantage is lost and the 
antenna exhibits essentially 
horizontal poiarization unless 
it is aimed at the satellite 
with an elevator rotator. 
Obviously, an azimuth rota- 
tion is of no advantage, as its 
azimuth pattern is essentially 
omnidirectional. 

Construction of the turn- 
stile is merelv an extension of 



the technique used for the 
single dipole over a ground 
plane (Fig. 2). Two additional 
dipole elements are installed 
on the plastic disc at right 
angles to the original dipole 
(see Fig. 3). To obtain cir- 
cular polarization, a one- 
quarter wavelength phasing 
line fabricated from RG-405 
rigid coaxial cable is con- 
nected between the dipole 
elements. This phasing line is 
bent into a loop and sup- 
ported by its solder joints. 



COfiSTRUCTIC 



£CHfMj:i iCiLLf 



D-PO^E NO ; 




Fig. 3. Turnstile over ground plane. 



C'fiSrffUCT''OfJ- 



= TiSiKG l;\e 



IN^UL^ri" -l^-V COi^ 




SiSe I S£Q'D> 



^ a£:.Z ELEMENTS 
v--" CC.VN 45^f PJ^Ri— EU 
■tV.TH S^OLiljr. p_,irjE : 



SOL^£= tLL. 3^f.15 



AZIMUTH P^Tr^f^N 




OFF DIPOLE 

ENDS 
/ 



ELEVATIOfJ PATTERN 



OVERHEAD 




r-i~ 



Ue^ 



SlOES id PiQ Ij) 



Mji~;.^1i.L - ii""-:."INU\: -R CO=?E= SH£ = 



fGLi^i^tlATlOf^i- 



/^ 



^ 



SKEWED LINEAR 
HOP 6 VERT 



Fig. 4. Sloped turnstile over conformal ground plane. 



Detail X of Fig. 2 is also 
applicable for mounting and 
feeding this antenna configur- 
ation. 

If the element lengths, line 
lengths, and spacings listed in 
Table 1 are used, vswr should 
nor exceed 2 to 1 over the 
satellite bandwidth. A near 
perfect match may be 
achieved by trimming the 
element lengths and their 
spacing off the ground plane. 
Adjusting the phasing line 
length for perfect circularity 
overhead is possible but not 
critical in this application, as 
some ellipticity overhead will 
be of little consequence. 

Sloped Turnstile Over 
Conformal Ground Plane 

A developmental antenna 
presently in use at K20VS 
was designed and constructed 
to overcome one of the major 
drawbacks of the antenna 
previously described. All the 
monopole and dipole con- 
figurations exhibit either ail 
vertical (monopole) or all 
horizontal polarization on the 
horizons, thus creating polari- 
zation fading 'when the satel- 
lites tumble and rotate. A 
combination of vertical and 
horizontal polarization [slant) 
at the horizons would be an 
advantage in obtaining the 
more uniform performance 
for all orbiting satellite orien- 
■ tations. 

Thus the elements of the 
basic turnstile were recon- 
figured at a 45 degree angle 
and the ground plane beneath 
them., was shaped to be 
parallel with each element. 
Overhead, the antenna is still 
essentially circu larly 
polarized with slightly less (1 
dB or so) gain than the simple 
turnstile, but the overall gain 
in uniform performance is 
worthwhile. In actual tests at 
this station, no measurable 
difference in overhead perfor- 
mance was observed between 
this antenna and the turnstiie. 

Basic feed and phasing line 
construction is identical to 
the turnstile (Fig. 3), and the 
feedpoint connector is 
mounted on the base ground 
plane similar to Detail X In 
Fig. 2- The elements (Fig. 4) 



26 



are bent down at a 45 degree 
angle to the horizontal and a 
conformal ground plane is 
fabricated from either alum- 
inum sheet or thin copper or 
copperclad printed circuit 
board material. The use of 
thin copper sheet allows the 
ground plane assembly to be 
soldered together with a 
250-300 Watt soldering iron 
or torch. 

Again, dimension adjust- 
ments may be required if 
close matching is desired. 
Furthermore, slight adjust- 
ments {±10 degrees) in the 
element droop angle will also 
affect the vswr (and the 
pattern). This angle adjust- 
ment should be used only as a 
final tune-up step. Element 
lengths have the largest effect 
on vswr. 

Results from this antenna 
were surprising. The 432 MHz 
prototype was completed five 
minutes before a Mode B pass 
favoring US east coast-Europe 
contacts. A six-foot 
piece of RG-58 was tem- 
porarily connected to the 
antenna and the KLM Echo 
70 (10 Watts output). Three 
western European stations 
were worked on that pass 
with no difficulty. No in- 
ference is intended that this 
design is the ultimate omni- 
directional antenna. Rather, 
it is presented as an example 
of an unorthodox design 
which can serve as a starting 
point for further develop- 
ment and experimentation. 

Summary 

As with all antennas, good 
horizon coverage is a function 



Reference F igures 



Use 



A 



B 
C 



E 



1,2,3 



Ground plane 

edge size 
1,2,3,4 Radiator length 

2,3,4 Ground plane 

spacing 
3, 4 Phasing line 

length 
4 Triangle height 







Dimensions 






146 WIH 


z 


432 Mt- 


z 


435 WIH 


2 


IM 


CM 


IN 


CM 


IN 


CM 


40.5 


102.8 


13.7 


34.7 


13.6 


34.5 


20.2 


51.4 


6.9 


17.4 


6.8 


17.2 


17.8 


45.2 


6.1 


15.3 


6.0 


15.2 


12.1 


30.8 


4.1 


10.4 


4.0 


10.3 


28.5 


72.4 


9.6 


24.5 


9.5 


24.3 



Table 1. Physical dimensions. *Minimum sizes. '**Note: Assumes velocity factor ^ 0.6. For 
different coax, use y4 wavelength electrical lengtli. 

of the height of the antenna. 
These antennas perform well 
overhead and at higher eleva- 
tion angles almost indepen- 
dently of their physical 
height above ground, but per- 
formance out at 2,000 miles 
(satellite near the horizon) 
couid be severely compro- 
mised by terrain blockage. 
Good low angle (DX) cover- 
age is best accomplished with 
a unidirectional array, such as 
a yagi or coHinear, mounted 
high and in the clear. An 
existing VHP array with 
azimuth control in conjunc- 
tion with an omni type anten- 
na for higher radiation angles 
is an ideal combination for 
all-around satellite work. 

As stated before, the 
antennas described here are 
hardly the ultimate in omni- 
directional types. Further 
development and experimen- 
tation is most rewarding with 
antenna design. For example, 
the sloping turnstile might be 
further improved by extend- 
ing or reshaping the ground 
plane, adding an additional 
set of dipole elements at a 45 
degree angle above the 
horizontal, adjusting the 
droop angle, etc. Accurate 



comparisons of several 
antenna designs can be made 
quite easily using the satel- 
lites themselves as an antenna 
range signal source. A typical 
pass of 20-25 minutes permits 
switching between the 
antennas under test and 
evaluation of the results. 
IVlodification may be accom- 
plished in time for the next 
pass. The actual pattern of an 
antenna may be estimated by 
physically holding the anten- 
na (particularly 432 MHz 
versions) and rotating it while 
pointed at the satellite (to 
estimate circularity), chang- 
ing its elevation orientation, 
etc. Fading effects from the 
satellites themselves tend to 
be of relatively slow duration 
(3-4 minutes), so measure- 
ments or comparisons made 
within 2-3 minutes effectively 
eliminates errors caused by 
the satellites or atmospheric 
conditions. 

Gain estimates for higher 
gain VHF arrays may also be 
made using the satellite by 
switching back and forth 
between a reference antenna 
(e.g., dipole) and the antenna 
under test while observing the 
received signal level on the 



station receiver. A calibrated 
attenuator will permit more 
accurate measurements. Set a 
level with the reference 
antenna, switch to the gain 
array, and insert attenuation 
in the antenna line until the 
received level is the same as it 
was with the reference 
antenna. The gain of the 
array may then be read off 
the attenuator dial. Ob- 
viously, different line losses 
must be accounted for and 
the polarization of both 
antennas should be the same. 
The present OSCAR satel- 
lites are providing the 
amateur fraternity with a 
unjque opportunity for 
VHF-UHF antenna experi- 
mentation. Future "sta- 
tionary" (geosynchronous) 

-satellites may serve as per- 
manent antenna ranges in the 
sky, permitting extended 
developme.nt, adjustment, 

..and measurement times for 
antenna work. 

It is hoped that the ideas 
presented here will encoura^ 
further experimentation and 
development in VHF-UHF 
antennas and fill a need for 
the present OSCAR satel- 
lites.". 



Looking M/est 



from page 23 

way of phone service was being over- 
loaded with traffic. IVIuch of the com- 
munications handled by amateurs was 
what might best be termed of the 
"health and welfare" variety, per- 
mitting firefighters to get word to 
their relatives as to where they were, 
locating people for other people, etc. 
It should be noted that firefighters 
came from all over the USA, and for 
many there was but one way to get a 
message to the "folks back home": via 



amateur radio. Amateur communica- 
tions was not limited to this small 
aspect, however — not by a long shot. 

Both VHF repeaters and HF point- 
to-point were used to relay informa- 
tion to and from areas where the fire 
was being fought, relay firefightlng 
orders, and handle just about every 
conceivable form of traffic that you 
might imagine, in all, over three 
hundred amateurs (under the direc- 
tion of Ed Gribi, emergency coor- 
dinator for the area) from alt over the 



state (and even from out-of-state) 
volunteered their services at one time 
or another. I am told that no offer of 
help was turned down. 

Repeater systems served well and 
continue to do so. At least two 
machines were brought into the area 
by concerned amateurs who realized 
the communications need. One came 
from a group at Vandentaerg AFB, and 
was installed at the Hunter- Liggett 
Military Reservation near Paso Robles, 
to give coverage from the Ouesta 
Grade to Salinas. Its channel pair is 
.2S/.8S, and it's under the trusteeship 
of W6LI0. I've also been told that the 
.34/. 24 group out of the Bay area 
literally "smoke tested" their new 



Motorola repeater (destined for 
service atop Mt. Diablo} by installing 
it In a portable configuration at a 
point near the northern tier of the fire 
area. It performed flawlessly. Again, 
it's hard to know exactly what's trans- 
piring since I am forced to report 
from secondhand information rather 
than from an eyewitness viewpoint. 
Suffice it to say that amateur radio 
and its people have done and are 
doing their share and mcn'e to aid in 
the formidable effort to stop the 
raging infernos. They are giving their 
time, talent, and equipment because 
there is a need and a job to be done. I 
am proud of each and every one of 
them. They know and they care. 
They're getting the job done. 



27 



Get Set 
For OSCAR 8 



'- details on the new bird ! 




Fig. 7. Up, up, and away! This photo of tile OSCAR 7 iaunch 
shows what's in store for AlViSA T-OSCA R D. 



Gary L. Tater W3HUC 
7925 Nottingham Way- 
Eliicott City MD 21043 



Five, four, three, two, 
one, b!ast-offi Soon a 
new amateur satellite will be 
carried into Earth orbit. Are 
you ready to start making 
contacts via this new satel- 
lite? If not, read on, and 
you'll discover what you need ■ 
to use AMSAT-OSCAR D {to 
be called AMSAT-OSCAR 8 
after a successful launch). 

Why AMSAT-OSCAR 8? 

Because AMSAT's Phase 
III spacecraft will not be 
operational until early 1980 
and OSCAR 6 cannot be 
counted on until then, 
AMSAT felt that AMSAT- 
OSCAR 8 would provide a 
continuation of the existing 
amateur satellite program and 
insure that amateurs would 
have a reliable satellite for 
communications over the 
next few years. 

One major objective of the 
AMSAT-OSCAR 8 (AO-8) 
mission is to provide a satel- 
lite for use as an educational 
tool in schools. Other objec- 
tives include the continuation 



of demonstrations by stations 
in the amateur satellite ser- 
vice, experimenting with the 
feasibility of using satellites 
with small amateur terminals 
for bush communication, 
emergency communication, 
communication between 
medical centers and isolated 
areas, aeronautical, maritime, 
and land mobile communi- 
cations, direct satellite to 
home voice broadcasting to 
simple amateur receivers, and 
other similar applications. 
Further objectives are to 
demonstrate special operating 
techniques that enhance the 
usefulness of low orbits for 
these satellite applications 
and to lest a new communi- 
cations transponder fre- 
quency combination for 
improved operation for 
moderate power amateur 
stations. 

Building the Satellite 

For longer than a year 
now, AMSAT members from 
many countries have been 
planning, designing, and 
building a satellite called 
AMSAT-OSCAR D. Because a 
project like this is extremely 
complex, it takes many 
amateurs, pooling all their 
"knowledge and abilities, to 
turn the stringent design and 
reliability requirements into a 
ready-to-launch satellite. 

Some of the complex 
issues that had to be settled 
and turned into hardware 
were the receivers and trans- 
mitters for the transponders, 
the antennas and antenna 
deployment system for the 
large antennas, the satellite 
stabilization system, the 
power system, and hardware 
both in the satellite and on 
the ground for commanding 
the satellite. As a user, you're 
primarily concerned with the 
transponders that make satel- 
lite communications so much 
fun, but there are really 
eleven major subsystems in 
AO-D: 

1 . 2m to 70 cm tran- 
sponder; 

2. Two to ten meter 
transponder; 

3. Morse code telem- 



28 



1 . Japan AMSAT Association 2m to 70 cm Transponder — Mode J 

• Input frequency passband between 145.90 and 146.00 MHz. 

• Output frequency passband between 435.10 and 435.20 MHz. 

• Power output is 4 Watts PEP. 

• Downlink passband is inverted from upMnk passband. 

• Linear operation — SSB and CW are preferred modes. 

• Morse code telemetry beacon at 435.095 MH^. 

2, AMSAT Two to Ten Meter Transponder — Mode A 

• Input frequency passband between 145.85 and 145,95 MHz. 

• Output frequency passband between 29.40 and 29.50 MHz. 

• Downlink passband is not inverted from uplink passband. 

• Linear operation — SSB and CW are preferred modes. 

• Morse code tsfemetry beacon at 29.40 MHz. 

Table 1. Summary of A MSA T-OSCA R D transponders. 



Ch. 1 Total solar array current 

Ch. 2 Battery charge-discharge current 

Ch. 3 Battery voltage 

Ch. 4 Baseplate temperature 

Ch, 5 Battery temperature 

Ch. 6 Rf power out. — Mode J 

Table 2. Morse telemetry channels. 



etry system; 

4. Satellite command 
system; 

5. 10m antenna de- 
ployment system; 

6. Battery charge regu- 
lator; 

7. Soiar cells; 

8- Instrumentation 
switching regulator; 

9. Magnetic attitude 
stabilization system; 

10. Satellite structure, 
wiring, and rf cabling; 

11. 14-28 volt power 
switching regulator. 

Building a satellite like 
AO-D proceeds pretty much 
along the same lines as most 
electronic projects do. First, 
each electronic system is 
tested as a breadboard and 
then laid out for a printed 
circuit board. To insure that 
the satellite functions reliably 
for years, each integrated 
circuit, transistor, and diode 
is screened by burning the 
part in by applying power to 
the part for several hundred 
hours. Then the component is 
mounted onto a printed 
wirirjg board. After each 
system is mounted in the 
satellite structure, the satel- 
lite is tested under the 
vacuum conditions and 
temperatures it will see in 
space. Because amateur satel- 
lites are launched on a space 
available basis, they are 
mounted on the launch vehi- 
cle neatly tucked under the 
primary sateilite as you can 
see from the accompanying 
pictures. In Fig. 3 you can see 
Dave W60AL inspecting the 
electrical connections for the 
pyrotechnical shears which, 
when fired, cut the Marmon 
clamps that released OSCAR 
7 from the Delta launch 



vehicle. A heavy duty spring 
then ejects the satellite into 
its orbit path. A few seconds 
later, the ten meter antenna is 
deployed by a pyrotechnical 
shear mechanism aboard the 
spacecraft. 

Getting Ready 

There will be two com- 
munication transponders on 
AO-8 for which you will need 
equipment. Only one tran- 
sponder will be operated at a 
time because of spacecraft 
battery constraints. 

The Mode A transponder 
is a two to ten meter unit 
similar to the one on 
AMSAT-OSCAR 7 and has 
the same frequency plan 
(input frequency passband 
between 145.85 and 145.95 
MHz, output frequency 
passband between 29.4 and 
29.5 MHz), You should plan 
to use about 80 Watts erp 
made up of output power 
from your transmitter, coax 
cable losses, and antenna 
gain. A ten meter preamp 
should stand you well for 
copying the Mode A down- 
link. 

The second transponder, 
constructed by members of 
the Japan AMSAT Associ- 
ation in Tokyo, uses a two 
meter input, 435 MHz output 
frequency combination which 
has not yet been flown in the 
AMSAT Phase II series. This 
transponder, designated Mode 
J, operates with an input 
frequency passband of 
145.90-146.00 MHz, and an 
output frequency passband of 
435.10^435.20 MHz. The 
power output is 4 Watts PEP, 
so a small 435 MHz antenna 
should produce a strong 



signal to your receiver. As 
noted in Table 1, the output 
passband is ir^verted, i.e., 
upper sideband uplink signals 
become lower sideband 
downlink signals. The same 
transmitter you use for Mode 
A can be used on Mode | . 



Antennas 

In general, simple antennas 
such as ten meter dipoles and 
four element 2m and 70 cm 
beams will provide excellent 
results. The AO-8 Mode J 435 
MHz downlink antenna is a 
simple monopole and will 
provide a linearly polarized 
signal. Likewise, the space- 
craft's Mode A ten meter 
downlink antenna is a linearly 



polarized dipole, oriented 
perpendicular to the stabili- 
zation magnet in the space- 
craft as in AMSAT-OSCAR 6. 

Although you can transmit 
on two meters to the satellite 
using a linearly polarized 
antenna and get good results, 
if you are a perfectionist, you 
might like to try circular 
polarization. 

Both the Mode A and 
Mode J transponders on AO-8 
use the same receiving 
antenna, a canted turnstile 
comprised of four 18-inch 
lengths of J4-inch carpenter's 
rule fed by a hybrid and 
matching network so as to 
develop circular polarization. 
One- port of the hybrid feeds 
the Mode A receiver such that 




Fig. 2. Jan W3GEY inspecting OSCAR 7 on the Delta launch 
vehicle. 



29 



left-hand circular polarization 
is required by users in the 
Northern Hemisphere and 
right-hand circular polariza- 
tion in the Southern Hemi- 
sphere. A second port of the 
hybrid is connected to the 
Mode J receiver such that 
right-hand circular polariza- 
tion is required in the North- 
ern Hemisphere, and left- 
hand circular polarization in 
the Southern Hemisphere. 

Telemetry System 

So that everyone can 
watch the status and health 
of the spacecraft, AMSAT- 
OSCAR 8 will contain a six 
channel (Viorse code telemetry 
system. The Morse telemetry 
on 29.40 or 435.095 MHz 
will be set at 20 words per 
minute, but you can slow it 
down by recording it anci 
playing it back at a slower 
rate. You will hear the telem- 
etry as three digit numbers 



with the first digit being the 
channel number and the next 
two digits being the telemetry 
value. A sample telemetry 
frame would look like this: 
120 255 380 451 551 660 HI 
120 255. 

Although the equations to 
convert the telemetry values 
to engineering units have not 
been finalized as of this 
writing, the channel selec- 
tions have been made and 
they are listed in Table 2. 

Using AMSAT-OSCAR 8 

Once AO-8 becomes oper- 
ational and you've assembled 
your station, you can begin 
to make contacts picking up 
new states and countries each 
time you get on the salellite. 
If you need help, contact 
AMSAT at Box 27, 
Washington DC 20044 for the 
name of the nearest AMSAT 
Area Coordinator who, as an 
experienced satellite user, can 




give you a hand. 

In addition to making 
contacts and working new 
states through the satellite, 
AMSAT hopes that you will 
consider using AMSAT- 
OSCAR 8 to perform experi- 
ments and educational 
demonstrations. These efforts 
gain amateur radio much 
needed beneficial publicity 
and provide AMSAT with 
documented facts to support 
requests for future launches. 

Your experiments might 
begin with such simple 
experiments as using a power 
meter to plot the minimum 
power needed to hear your 
return signal in the downlink 
from your earliest acquisition 
of signal to loss of signal. 
Possibly you could measure 
the frequency change in the 
beacon due to the Doppler 
effect of the satellite's veloc- 



ity. 

As a guide to what you 
can do with AO-8, other 
experiments are listed in 
Table 3. Perhaps you can add 
some interesting experiments 
to this list. When you com- 
plete an experiment, be sure 
to write to AMSAT with your 
results, you will be contrib- 
uting to the future of ama- 
teur radio. 



Conclusion 

if you are already a user of 
OSCAR 6 and OSCAR 7, 
then you're set to operate 
through OSCAR 8, and you 
know how exciting satellite 
communications are. If you 
are not ready for OSCAR 8, 
then now is the time to get 
your station ready to join the 
fun. See you on AMSAT- 
OSCAR 8! ■ 



Fig. 

7. 



3. W60A L puts the finishing touches on AMSA T-OSCA R 



A) Educational demonstrations in schools and for youth groups. 

B) Ranging (distance measurement! experiments to determine satel- 
lite or user position. 

C) Doppler (range rate} measurements to determine satellite or user 
position. 

D) Emergency Locator Transmitter (ELT) experiments to locate 
downed aircraft or ships in distress. 

E) Small terminal user experiments using hand-held equipment, Or 
mobile terminals operated from an automobile, airplane, boat, motor- 
cycle or bicycle. 

F) Emergency communications demonstrations with portable equip- 
ment. 

G) Medical data transmission'esperiments, including the transmission 
of analog or digital physiological data (e.g., ECGs and EEGs). 

H) Data collection from remote, unattended ground terminals (rain 

gauges, wind gauges, etc.). 

1} ASCII data transmission experiments, including remote accessing 

of digital computers. ,. _^ __ 

J| Slow scan and medium scan television experiments. 

Kl Remote control experiments (such as radio control aircraft, 

garage door opener, remotely controlled kitchen ovens, etc.) 

L) Transponder interlinl<ing experiments between AO-7 Mode Band 

AO-8 Modes A and J. 

M) Multiple access experiments (such as quantitative experiments to 

evaluate the effects of power sharing -with different modulation 

techniques}, 

N) Ground Station automation (closed loop monitoring of downlink 

signals and automatic adjustment of uplink power and frequet(cy). 

Ol Broadcast demonstrations using the transponder in a single access 

mode, evaluating performance for different modulation modes. 

P) Extended range communications experiments to attempt 

transmission or reception beyond the normal maximum satellite range. 

R) Low power (QRP) user experiments to determine the minimum 

power needed to sustain communications. 

S) Traffic nets scheduled on the sateiiite. 

T) Automatic tracking of ground station antennas in azimuth and 

etevaiion (either on an open loop or closed loop basis). 

U) Unattended, automatic telemetry data collection (e.g., using tape 

recorders for later analysis) , 

V) Unattended online or offline computer processing of received 

Morse code telemetry data, with printout of parameter ualtjes and units. 

Automatic decoding of Morse code characters in the presence of noise. 

W) Experiments involving physical parameters, e.g., determination of 

spacecraft spin characteristics and orientation from telemetry data. 

X) Traffic handling with RTTY using autostart techniques. 

Table 3. Experiments that can be performed using the 
transponders and telemetry system aboard AMSA T-OSCA R 8. 



30 



YOU... 
AM) MHSAT PHASEM 



■-'^.'^ 




.^\ h 



\i** 



An exciting new era in amateur radio 
is about to begin ...the era of AMSAT PHASE 
III OSCAR satellites. 

Many of you are familiar witti the bene- 
fits of the AMSAT OSCAR satellites, notably 
OSCAR 6 and 7. These satellites, with a com- 
bined total of over 8 years in orbit, have 
provided communications between amateurs 
throughout the world. They have also pro- 
vided a capability for an educational program 
in space sciences and many interesting 
experiments. 

AMSAT, with members and contrib- 
uting groups worldv^ide, and headquarters in 
Washington, D. C, has been responsible for 
our current satellite program. Many people 
feel that perhaps the greatest value of the 
amateur satellite program is the dramatic 
demonstration of amateur resourcefulness 
and technical capability to radio spectrum 
policy makers around the world. 

The value of this aspect of amateur radio 
as we prepare for the 1979 World Adminis- 
trative Radio Conference OA/ARC) is enormous. 

The AMSAT PHASE III satellite pro- 
gram promises a continuing demonstration 
that amateur radio is at the forefront of 
modern technology. PHASE III satellites will 
routinely provide reliable communications 
over paths of up to 11,000 miles (17,600 km) 
for 17 hours each day. You can think of them 
as a resource equivalent to a new band. 

The cost of these PHASE III satellites 
is a projected $250,000. Commercial satel- 
lites of similar performance would cost nearly 
$10,000,009. 

Your help is needed to put these 
PHASE III OSCAR satellites in orbit. 



Your valued, tax-deductible contribu- 
tion can be as small as one of the 5000+ 
solar cells needed. A handsome certificate 
will acknowledge the numbered cells you 
sponsor for $10 each. Larger components of 
the satellites may also be sponsored with con- 
tribution acknowledgements ranging to a 
plaque carrying your name aboard the satel- 
lites. Call or write us for the opportunities 
available. 

Your membership in AMSAT Is impor- 
tant to the satellite program, and will give 
AMSAT a stronger voice in regulatory matters 
concerned with satellltes^At $10 per year or 
$100 for life, you will be making a most signifi- 
cant contribution to the satellite program and 
the future of amateur radio. You will also 
receive the quarterly AMSAT newsletter 

Clip the AMSAT PHASE III coupon 
below and send your support today, or call 
202-488-8649 and charge your contribution 
to your BankAmericard (VISA) or Master 
Charge card. 




AMSAT PHASE II! *^* 

Radio Amateur Satellite Corooration 
Box 27. Washington. D. t. 20044 

202-488-8649 

YES, I want to support AMSAT PHASE III OSCAR 
satellites. Enclosed is: 

C S in sponsorship of solar cells ((ss $10 each) 

C $10 Annual membership H $100 Life membership 
G Send information on sponsoring larger satellile com- 
ponents. 



n 



L 



Name 


Call 


AMSAT Member? 


Slrsel 


Ciiy 


State 


Zip 



J 



Fred J. Merry W2GN 

35 Highland Drive 

East Green bush WY 12061 



Build An OSCAR 
2m Transverter 



-- make QRP days a success! 



There are in use on mode 
B of OSCAR 7 possibly 
200 28-432 MHz transmitting 
converters rnade originally by 
tlie Carmichael Communica- 
tions Co. and more recently 



by the Amateur Radio Com- 
ponent Service. Using an 
antenna system with a 
modest gain, with 4 to 5 
Watts output on 432 MHz, 
these converters seem made 




to order for low power 
satellite operation. There are 
many mode B users who vvJIi- 
attest to their performance. 
VVINU, for example, made 
about 200 QSOs on mode B 
with this converter and a 
mediocre antenna during his 
1976 Bermuda jaunt. Con- 
sidering the successful track 
record of this converter on 
432, its S.SB capability and 
the improved tube perfor- 
mance on 144, the idea of 
building a 2 meter version 
was attractive. 

The circuitry of the two 
meter model, shown in block 
form in Fig. 1, is the same as 



the 432 model except for the 
elimination of one stage in 
the LO chain and the 
appropriate changes in the LC 
elements. 

The schematic, Fig, 2, 
illustrates the simple straight- 
forward design characteristic 
of this converter. A voltage 
doubler circuit off the 6.3 V 
ac line provides the voltage 
for both the 2N4126 and the 
2N3866 stages and also the 
adjustable bias for the 6939 
amplifier. Zener regulation is 
used for the amplifier screen 
and for the crystal oscillator. 
The mixer is cathode biased, 
input jack j1 is terminated 
with a 62 Ohm resistor, 
which may be disconnected if 
the drive is too low with it in 
place. A 58.9 MHz crystal 
may be used if the available 
driver does not have 29.5 
coverage. This will give a 
mixing frequency of 28.1 
MHz for an output on 145.9 
MHz. 

Construction details are 
shown in the photos. The 
unit is built on a Bud CU247 
cast aluminum chassis, using 
the top as a mounting base. A 
brass partition lengthwise 
isolates the LO chain, which is 
built on a circuit board. The 
mixer and amplifier shielding 
is provided by two lateral 
partitions. Five small brass 
tabs on the partitTdns provide 
■ a connection to the bottom 
of the chassis to complete the 
shielding when the unit is 
placed in the case. Although 
the construction is a bit 
fussy, experienced builders 
will 'have no difficulty in 
duplicating either the 2 meter 
or 70 centimeter converters. 
For those interested in 
building, a complete set of 
information, drawings, and 
photos covering the two 
meter converter (and its 220 
MHz and 432 MHz counter- 
parts) is available from 
ARCOS, PO Box 546, East 



J 




The complete transverter. 



Fig. 1. 



32 







Foil side, local oscillator board. 



Parts side, local oscillator board. 




Underside of the amp and mixer. 



Greenbush, NY 12061, for $5 
(to cover costs and postage). 
These converters are also sold 
by ARCOS as assembled and 
tested units. 

For alignment, an output 
indicator of some kind is 
needed, and it is best to also 
have a two meter receiver 
tuned to the output fre- 
quency (observing the S- 
meter as a tuning indicator). 
The oscillator and doubler 
stages may be tuned using an 
rf probe and meter to max- 
imize output. A counter, if 
available, coupled loosely to 
L2 will confirm that the 
mixing frequency is correct. 
The rf voltage at the point of 
connection to the output 
coax from the circuit board 
should be 5 or more volts ac. 
The mixer and amplifier 
stages of the two meter 
version of this converter do 
not appear to have any 
instability problems, although 
there is a tendency to oscil- 
lation if the mixer grid circuit 
is mistuned to approach the 
operating frequency. Spuri- 
ous outputs, with proper 
alignmenl;, appear on the 
Tektronix L-20 to be over 40 



dB down. At this low power 
level, interference with other 
two meter operations is un- 
likely and, at least in the 
Albany NY area, has not been 
experienced. (More than we 
can say for some commercial 
units we have tried to use for 
satellite work.) 

If you haven't yet tried 
low power, there are still 
some surprises ahead for you 
in satellite operation. " 



Transmitting converter amplifier and mixer. Note intercom- 
partmental shielding utilized to Insure stability. 

Coil Data 

LI -9T- tap at 2V2I - '/* in. diam. - #18 wire -3/4 in. long 

L2 - 5T - tap at IT — Vi in. diam. —#18 wire — 3/4 in. long 

L3 — not used for 144 

L4 - 1 YaT Yi in. diam. - >4 in. leads — #22 insul. wire 

LS - 3>4T Yi in. diam. - 1 1 /S in, leads - #16 wire 

L6— 5T — Vi in. diam. — % in. leads — #1 6 wire 

L7 -4T -3/S in. diam. -% in. leads -#16 wire 

L8 — S'/sT — '/s in. diam. — 1 1/S in. leads —#16 wire _. 

L9 — IT — 14 in. diam. — 3/4 in. leads —#22 ins. wire 

Variable Capacitors — Air Type 

01, C6- 1 to6pF 

C2, C3, 04, 05 - 2 to 1 1 pF butterfly type 



@250VDC 




^63V.aC 



Fig. 2. 



33 



Pat Gowen C310R 
17 Heath Cres. 
Hellesdon 
Nori'/ich NR6 6XD 
Norfolk 
England 



Predicting OSCAR 
Propagation 



-- not always simple 



The earliest case of un- 
expected radio propaga- 
tion from an artificial satellite 
took place in early October, 
1957, soon after the launch 
of SPUTNIK 1. Radio ama- 
teurs observed good copy of 
the world's first man- 
launched satellite on 20,005 
MHz when it was on the 



opposite side of the Earth to 
the listener, but not always 
when It was to be expected, 
coming up over the horizon. 
Those observations made 
during the relatively short life 
of the spacecraft tended to 
indicate that good conditions, 
e.g., a high MUF, were coinci- 
dent with both of the notice- 



able effects. Sub-F2 layer 
reflections during the high 
sunspot years with the conse- 
quent high level ionization 
were apparently responsible 
for the antipodeal signal, with 
the attenuation of lower 



layers limiting the signal at 
low angles when the maxi- 
mum density path was 
between the beacon and the 
listener. 

A similar effect was appar- 
ent on some of the earlier ten 
meter beacon OSCAR space- 
craft.'- '^ With ihc advent of 
the OSCAR 6 and 7 Phase li 
spacecraft in high orbit, well 
above the maximum possible 
F2 layers and launched 
during low sunspot years, 
similar happenings could 
hardly have been predicted. 
Although infrequent, such 
abnormalities have been evi- 
dent.^ ''^'^ '* 

Evidence of beyond-the- 
horizon audibility of both the 
145 and 435 MH/_ beacons is 
very rare, but early hearings 
and late losses have been 
reported, although rarely for 
more than three minutes 
from the calculated AGS or 
LOS time. One would hardly 
expect effects like forward 
scatter to be evident when 
. the signal source is of less 
than one Watt erp due to the 
attenuation placing the small 
signal source well below the 
noise level ai the receiving 
end. 

There is, however, con- 
■ siderable evidence of the two 
meter uplink of OSCAR users 
accessing the satellites 
for up to seven mTriutes after 
.-the time when, according 
to path theory and calculation 
geometry, the signal should 
have ceased to be tran- 
sponded by the spacecraft. 
They, regrettably, fell far 
short" of the thirty minute 
extra presence of the 29 MHz 



■'NORWAL" C0^JDIT|■D^5 

Tjoor." con:iit o^js 



" *fln«AL' CONDITIONS 




MIWUTES BEFORE PREDICTED A OS 



3 ^ T) '^ 7 9 9 10 II 
MINUTES POST A 5. 




e li 11 15 



Fig. 1. OSCAR 7 29.502 MHz beacon down/ink strength 
through time in typical different conditions (HF). 



Fig. 2. OSCAR 7 returned (145.95 IVlHz) signal on 29.5 MHz 
downlink in typical different conditions (f/F). 



34 




"FAIR" ) 



HF PROPAGATION 
AT EXTE^JOED MUf 



Fig, 3. Contour mapping of maximum distance A 0-6 and 
A0-7A 10 meter detection on polar equidistant projection. 
Polar areas of no subsatellite points are mariaed "+" as tliese 
are non-definable. Note the distortion of horizon radius circle. 
This is an effect of using an equidistant projection centered on 
the pole axis. A stereographic projection would show a true 
horizon circle, but its center would not he at the observer's 
specific QTH. A great circle map centered on the observer's 
QTH would form a true circle with location center, but would 
further distort distant contours. 



downlink, thoughj and rarely 
accessed both at the same 
tlme.^'* 

Equally unfortunate is the 
fact that rarely does the 432 
MHz uplink seem to exceed 
the line of sight by more than 
about one-and-a-half minutes, 
within the limitations of my 
experience. 

What appear to be 
anomalies between the 
various frequencies' behavior 
patterns and the apparent 
contradictions to currently 
accepted textbook theories 
may be the subject of a 
future article when a suffi- 
ciency of data has been 
gathered to give a reasonably 
statistically sound degree of 
collated evidence. Already 
the information obtained and 
its relationships to other 
phenomena of interest to the 
radio amateur are enough to 
show the value of the OSCAR 
satellites in fields other than 



those of through-satellite 
communication alone.'' 

The following associations 
between what can be found 
by listening and using 
OSCAR for two-way com- 
munication, and what may be 
forthcoming by way of HF, 
VHF, and UHF (including the 
effects of aurorae, tropo- 
spheric and sporadic E in 
communication conditions), 
will be evidenced in. an 
attempt to show that the 
amateur radio satellites can 
give a valuable pointer to 
assist those keen to exploit 
the improved, and in some 
cases impaired, propagation 
that is effected. 

The Standard 

Many means of extrap- 
olating the precise crossing 
times of the satellite over 
one's horizon, calculated 
from the equatorial satellite 
crossing time and position. 



\ 6 S JO 12 |i; 16 IS 20 22 2^ 2ft 2fl i 

APPARENT MAXIf^UM FREOUEIyCY OP MODERATE ACTIVITY IN MEGAHERTZ 
E G OBSERVERS EQUATION TO MUF 



Fig. 4. Plot of all values of 
apparent. 

nowexist.^''''"-''''^'^^''^ 
The relationships that I shall 
use are those related to my 
own QTH/QRA, just North 
of Norwich, Norfolk, Eastern 
England, at 52° 40' N, T 10' 
E. For fine precision, albeit 
marginal in the wide field 
employed, the station's 
height above sea level plus the 
antenna height is given as 
160 feet. With no hill hTgher 
than my elevation within the 
horizon curve, wc may 
evaluate an addition as: H = 
1 .42 Ve", where H is the 
horizon extension in miles, 
and E is the elevation above,, 
sea level i n feet. In my case H 
= 1.42 V (95 + 65) = 18 
miles. That is neither here nor 
there in terms of the 3000 
mile slant range of OSCAR at 
horizon, but could add con- 
siderably to those in mile 
high cities like Denver and 
Mexico. Any blocks to true 
horizon may be found by the 
examination of contour maps 
and plotting out the height 
against distance on graph 
paper to find the true con- 
tours of the radius of true 
horizon around one's QTH. 
(Fortunately, flat old Norfolk 
suffers from no high hills.) 

We now have a means of 
finding the precise time, say 
plus or minus 15 seconds, 
when the satellite comes into 
our capture, (f there is no 
barometric lift, minimum 
soiar activity, and it is well 
into the night, OSCAR will 
appear exactly on schedule, 
almost simultaneously on the 
29.502, 145.971, and 435.1 



extension to horizon to MUF 

MHz beacons. One's 432. 125- 
175 or 145.900-146.000 
(OSCAR 6) or 145.850-950 
MHz (OSCAR 7 mode A) 
uplinks will appear as tran- 
sponder output at almost the 
same time. Any deviation of 
these times, relative to each 
other or to the calculated, 
will indicate an anomaly and 
show an alternative to "no 
propagation" conditions. 

High Frequency Conditions 

Although the variation on 
calculated AOS and LOS 
times is not always con- 
sistent, the genera! and 
'average effect may be seen on 
the graph values of Figs. 1 
and 2. At this point let me 
say that ! do not fee! that a 
- -sufficient number of measure- 
ments have been taken to 
fully substantiate the effect, 
as time, particularly during 
daylight hours, is very 
limite.d. Furthermore, a 
number of specific variables 
need to have attention, e.g., 
the path preference of normal 
HF communication at the 
time of measurement, the 
skip distance, and a further 
relationship to the time of 
year. It did seem that ultra- 
distant OSCAR audibility was 
more consistent with short 
skip conditions, i.e., ioniza- 
tion of the lower layers, than 
with long skip propagation 
associated with the F2 layers. 
But more work needs to be 
done on this subject. What 
was apparent from the orbits 
sampled was threefold; 
1. The higher the apparent 



35 



usable frequency was, the 
weaker the OSCAR downlink 
signal was on 29.502 MHz 
prior to horizon loss of signal 
predicted time, and the 
weaker it was at post-horizon 
at acquisition of signal times. 

2. The increase of maxinnum 
usable frequency for HF 
communication was indicated 
also by the strength of the 
downlink signal prior to 
expected AOS and after 
expected LOS. 

3. The high frequency propa- 
gation possibilities tended to 
coincide with an increase of 
the lime for which the ten 
meter downlink and beacon 
were audible both before 
official AOS and after its 
LOS. 

A further factor is the 
increase of noise, both on the 
downlink frequency band 
itself, and upon the tran- 
sponder's own downlink. 

At this point, two require- 
ments must be pointed out. 
The first is that the observer 
must be equipped with a 
reasonably high antenna, 
preferably with some gain, as 
high gain at low angle is an 
essential to observe these 
proximate-to-horizon effects. 
It is assumed that the keen 
DXer will have this require- 
ment. Second, it is normal to 
copy reasonably good signals 
both before and after the 
above-horizon transit for up 
to three minutes if the path is 
in daylight. In low iVlUF dark 
path conditions, the signal 
will normally extinguish 
promptly at the predicted 
LOS and arise promptly at 
AOS. We may summarize by 
saying that the longer and 
slower the beacon signal 
decays, the better the pre- 
dictor value for favorable HF 
conditions. 

Fig. 3 shows the contour 
lines found at this QTH with 
the extra path OSCAR detec- 
tion, i.e., anything observable 
above noise in three sets of 
subjective HP propagations. 
These .are grouped into 
"good," shown by the con- 
tinuous contour, "fair," as 
shown by the dashed con- 
tour, and "nil," as shown by 
the dotted line, which 



equates the line-of-sight path 
to the satellite. 

While we are dealing with 
HF conditions, let us mention 
that curse to the HF man, 
and the blessing to the VHF 
enthusiast - aurorae. The 
period leading up to an 
aurora will commence with 
an elevation of the symptoms 
of good conditions, with an 
added symptom of greatly 
increased noise and a marked 
deterioration of the quality 
(to use another subjective 
term) as the satellite nears the 
polar areas. Immediately 
preceding the actual event, 
transponded signals will be all 
but wiped out by noise and 
suffer from severe particulate 
modulation sounding like an 
old spark transmission. The 
signals may still be heard 
post-horizon in the noise for 
up to several minutes before 
total loss. More will follow on 
this subject in the VHF con- 
texL 

Very High Frequency Condi- 
tions 

The main indicators of 
VHF openings are: 
I. A severe attenuation upon 



'\A. 



A05 . £ ,MIN5 
LOS - :? MINS 



*iCS ■ SMtNS 



^ ^ E G Z M It IS 20 22 2*; 26 23 2C 

^PFAHEN^ MUF I ,\ MEGAHERTZ 

Fig. 5. Mean average signal strength of beacon to apparent 
MUFofsame values. 



one's own returned signal, 
with marked fluttering and 
very rapid QSB at high 
maximum to low minimum 
values when the satellite is at 
low elevations, i.e., just over 
the horizon at both AOS and 
LOS times. 

2. A marginal sub-horizon 
access with the signal popping 
up suddenly for very brief 
periods prior to and post the 
expected path times. 

The beacon at these times 
is marginally affected also, 
but not to anywhere near the 
extent of the uplink signal. 
With increasing elevation, the 
evidence decreases propor- 
tionately. At high altitudes, 



the effect is virtually unno- 
ticeable, and a normal access 
proceeds. To differentiate 
between the HF effect and 
the VHF effectj which do not 
always go together, it is 
necessary to alternately 
monitor one's own returned 
signal, and relate this to the 
beacon for comparison. To 
the observer, the transponded 
signal, even in good VHF 
openings, will rarely be heard 
more than two to three 
minutes at best on the down- 
link at extra horizon times, 
although other observers 
closer to the downlink have 
reported continuing copy for 
up to seven rninutes after 




Fig. 6. Horizon geometry. True Jine-of-sight path calculations and structure for control use. For 
ground range (subsatellite point to observer) (for use on great circle map), multiply Earth radius 
by angle formed by it and OSCAR radius in radians. This angle = = cos'^ of Rad 
Earth! Radius OSCAR = 3964/4884 = 0.81 16298 = cos Q = arcos of 0.81 163 in radians = 35° 
45' = 0.6238 radians. 0.6238 x 3964 = 2472. 7432 miles on great circle v- extra horizon. 

For horizon crossing point (by Pythagorus): Draw line from Earth's center to surface = 
Earth radius = 3964 miles (mean). Draw line from Earth's center to OSCAR = satellite path 
radius = 3964 + 920 = 4884 miles, which is the hypotenuse of the right angle triangle with 90° 
at the observer's point when "seeing" the satellite at horizon. H^ = A^ + B^ .'. rad. OSC2 -rad. 
Earth2 + slant ranged .'. rad. OSC^ - rad . Earth^ = slant range2 = 48842 . 39^42 = 23853456 - 
15713296 ^8140160 miles, s/ 8140160 = 2853 miles = slant range. 



36 



official extinction. It is also 
apparent at times of good 
tropospheric conduction that 
the predicted beam path is 
not always true. A swing of 
the beam carrying the uplink 
signal will often improve the 
downlink strength con- 
siderably by up to a 20° 
vartatiors in azimuth and 
some 30 in elevation. The 
normal polarization prefer- 
ence roll pattern^ ^'^'^'"'^^ 
is broken, with quite rapid 
changes in the preferred 
linear horizontal or vertical 
normal pattern that is usually 
serialized. 

The above effects mainly 
apply to characteristic be- 
havior indicating tropospheric 
openings. 

With sporadic E, the 
effects are similar, but, instead 
of the usual evening effects, 
are more normally present in 
the central day periods. Now 
the flutter and rapid fading is 
far more intense and takes 
place when OSCAR is at 
quite high elevations. Sudden 
extinction and pop-up of the 
uplink signal is far more 
evident. Observation of the 
VHF beacon also shows a 
similar pronounced effect, 
which, like the VHF uplink, 
is also subject to irregular 
polarization fluctuations at 
high elevation angles. 

Aurorae produce a degree 
of degradation on the 
stabiiity and tone of the VHF 
beacon as the satellite nears 
the auroral zone. But what 
are far more distinctive are 
the isolated uplink returns, 
which may be quite separ- 
ately effected with a tone 
"A" return on the ten meter 
downlink.^ ^'^° Often under 
auroral conditions, even 
separate GM stations have 
been observed with the char- 
acteristic auroral note, while 
other northerly stations have 
been virtually free and other 
more southerly stations 
totally free. This indicates 
that aurorae can be quite 
specific to a relatively small 
area, which is surprising, but 
readily and frequently ob- 
served. OSCAR gives a means 
for the early detection of 
forthcoming auroral openings 



prior to the spread to one's 
parochial observance area on 
the direct path. An even 
earlier indication can be given 
by the follow-on of a period 
of high MUF conditions due 
to enhanced solar activity by 
following the post-horizon 
ten meter signal, followed by 
northerly scintillation and 
tonal degredation. 

Ultra High Frequency Open- 
ings 

Ultra high frequency open- 
ings are difficult to detect by 
the ej>;clLisive use of OSCAR, 
but some small extension to 



the normal line-of-sight path 
can bo detected for periods of 
up to one minute. What is 
more noticeable is the slow 
rise of the transponded 
uplink signal returned down 
on the two meter band, as 
distinct from the more usual 
sudden arisal of the down- 
link. When openings are 
imminent, rapid flutter 
coupled with some difficulty 
of access at very low angles is 
observable. Possibly a better 
method is to calculate when 
stations in the workable area 
will be beaming at low angles 
over the top of your QTH as 



they track OSCAR, and place 
your receiver on that fre- 
quency corresponding with 
the appropriate uplink fre- 
quency on the 432.125 to 
432.175 MHz input to that of 
the 145.875 to 145.925 IVlHz 
downlink upon which you are 
hearing them, allowing for 
the Doppler shift.'-^^ It is 
quite amazing how many 
openings occur at 432 MHz 
when no QSOs are evident 
upon the normal direct path 
frequency range. It seems 
many listen, but few 
transmit, so everyone assumes 
the band to be dead. OSCAR 







Fig. 7. Possible theory for sub- or post-horizon audibility: At high IV! UF (dense ionospheric 
layer) times, the OSCAR signal may enter via less ionized areas according to solaf-radiation 
points. This is thought to be unlikely as its observed signal strength is greater than that 
expected by such a path. 




Fig. 8. OSCAR signal may enter through a low Ionized area, reflect from Earth, and then return 
to a reflective F2 area to be returned to observer. This is highly unlikely as signal strengths are 
far In excess of those expected (if any). 



37 



produces known activity on 
known frequencies with 
known beam directions and 
gives a valuable guide to the 
state of the band. 

The theories that may be 
advanced for the particular 
effects found can be 
numerous and complex. The 
number of variables are con- 
siderable, and an insuffi- 
ciency of observations have 
taken place to fully define 
any one single cause, let alone 
the multiple associations 
probable. It is hoped that 
perhaps someone with the 
time and equipment avaitabie 
may wish to take the investi- 



gations over, ideally, he 
would be equipped with iono- 
spheric sounding equipment, 
fine Doppler measurement 
for determining position and 
path, and narrow beam an- 
tennae. This article is 
intended to stimulate this 
approach, as well as to show 
readers that, whatever their 
field of interest within the 
wide framework of amateur 
radio, the AMSAT-OSCAR 
spacecraft are a valuable 
potential asset to their 
particular aspect. ■ 

References 

1. QST, October 1970, p. 74, 



"Australis Oscar-5 Ionospheric 
Propagation Results," Ray Soifer 
K2QBW Inow W2RS). 

2. Ca, May 1970, p. 60, "10 
Meter Anomalous Propagation 
with Australis Oscar-5," K.J. 
Doyle, 

3. Space Communications , 
ARRL Technical Symposium, p. 
85-91, "Oscar 6 over Western 
Europe," Pat Gowen G3IOR, 
September 1973. 

4. AMSAT Nev/sletter, Vol. VI, 
No. 2, 1975, "Abnormal Recep- 
tion of Oscar 6 Signals on Ten 
Meters," report by VU2UV. 

5. AMSAT Newsletter, Vol. VII, 
No. 4, December 1975, report of 
SDX QSO by Bud SchultzW6CG. 

6. AMSAT Newsletter, Vol. V!ll, 
No. 1, March 1976, report of 
same SDX QSO by Pat Gowen 
G310R. 




Fig. 9. Possible theory for sub- and post-hori/on audibility: At critically ionized areas, the 
OSCAR signal may enter as a conduction signal upon an "open-ended" duct at the dusk 
daylight attenuator, hence "conduct" to permit the observer to hear re-radiated signal from the- 
scattering Ionized belt. 



HORIZON 

L ^i-OF-ilGHr 




fig. 10. Possible theory for sub- or post-horizon audibility: simple refraction occurring due to 
angulation of signal as It transmits an area of higher ionic density. 



7. CQ-DL, No. 2, 1976, "Uber- 
reichweiten bei OSCAR-Satelliten 
im 10-m-Band," Dr. Waiter 
Eichenausr DJ2RE. 

8. "Keeping Track of Oscar," 
booklet published by R.S.G.B. 
from article series in Radio Com- 
munication by Bill Browning 
G2A0X. 

9. "escalator 6, QSL Card Orbit- 
al Calculator," Torsti Paatero 
0H2RK, OSCAR News No. 2, 
January 1974, p. 21. 

10. "The Wafland Calculator," 
OSCAR News No. 8, December 

1974, p. 17, DaveWalland. 

11. "The OSCAR 7 Look-up 
Chart," OSCAR News No. 12, 
September 1975, p. 21/22. Table 
plotter by Rudi Schoenberger 
DL8DF. 

12. "Oscar Prediction Look-up 
Tables," AMSAT-UK Handout, 
Tony Bailey G3WPO. 

13. "Oscar Tracking Computer 
Programmes," Jack Colsen 
W3TMZ, David WaMand, and 
Martin Sweeting G3YJO. 

1 4. AMSAT Newsletter, Vol. 
VIII, No. 1, March 1976. "Shoot 
Oscar with a Satellite," p. 6-14, 
Kazimierz Deskur K2ZRO. (First 
published in 73 Magazine.) 

15. OSCAR News No. 8, Decem- 
ber 1974, p. 5-7, Graphed Roll 
Patterns by G3I0R and G3PEJ. 

16. OSCAR News No. 11, June 

1975, p. 15, AO-7 Graphed Roil 
Patterns by G3I0R. 

17. OSCAR News No. 12, p. 18, 
September 1975, "Polarization 
roll graph," GSIOR". 

18. CO-DL, No. 2. 1976, 
"OSCAR-7-Auswer!ung der Tele- 
type-Telemetrie" Hermann Luer 
DL3SK,p. 38,39. 

19. OSCAR Nevjs No. 15, June 

1976, p. 3. "General News." 

20. AMSAT Ne'/jsletter , Vol. 
VIII, No. 1, March 1976, p. 27, 
Part of GE3IOR lener. 

21. OSCAR News No. 8, Decem- 
ber 1974, p. 1 2, "A calculator for 
finding Frequency Relationships, 
with positive and negative Dop- 
pler Shifts," 0H2RK. 



Further Reading 

"OSCAR Anaprop . . . Theory 
and Practice," GSIOR, in OSCAR 
News No. 5, August 1974. Pages 
15-18 give the mathematical 
formulae required for true hori- 
zon slant distances and sub- 
sateMite ground distances. 
Photocopies of OSCAR News 
items may be obtained from the 
AMSAT-UK librarian, G8KME, 
QTHR, at 3p. or equivalent in 
IRCs per page and postage cover- 
age. 

OSCAR News is the official 
journal of AMSAT-UK, Editor Dr. 
Arthur Gee G2UK, QTHR. Mem- 
bership in AMSAT-UK is £3-00 
minimum donation per annum, 
with forms from the Membership 
Secretary and Treasurer, James 
Keeler G4EZN,QTHR. 



38 



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Trustee V\/R3AHE 

Butler Countv Amateur 

FM Assoc. 

Mars PA 16046 



"The r^odel SCR 100 Receiver has 
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It in operation for nearly a year and 
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Stone Harbor Amateur 

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Dallas TX 



I The SCR1000 — simply the finest repeater available on the amateur market . . . and often compared to "commercial" 
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1055W. Germantown Pk., Norristown PA 19401 (215) 631-1710 

— .^^^^^^^— ^^^^^^^^— Formerly of Worcester PA rw , , , . t - 



S8 



39 



Fred J. Merry' V/2GW 

35 Highland Drive 

East Greenbusb NY 12061 



Try 
OSCAR Mobile 



-- the ultimate DX test! 



The availability of ama- 
teur ladio communica- 
tions via satellite has opened 
up an entirely new medium 
for reliable, long or short 
distance vehicular communi- 
cations. The amateur radio 
mobile station equipped for 
satellite communications is 
no longer limited by the 
range of terrestrial FM re- 
peaters, location, or HF 
propagation vagaries. For 
example, K81VIYN, using the 
simplest equipment in his 
vehicle, was abie to maintain 
consistent contact with the 



USA via the OSCAR 6 satel- 
lite from northern Canada 
and Alaska, when poor propa- 
gation conditions in that area 
rendered the HF amateur 
bands useless. Other amateurs 
have successfully used the 
satellites to communicate 
hom a boat in the Florida 
Keys, from an airplane over 
the Pacific, and from various 
automobile installations. The 
purpose of this article is to 
discuss how the OSCAR satel- 
lites may be used from a 
vehicle and give some ex- 
amples of equipment arrange- 




Today's equipment — 3 transceivers: 2m, 70cm and low band. 
The 2m FM is in tfje upper /eft. Solid state amplifiers for tf7e 
2m and 70 cm are in tiie trunl?. Antennas: 5/8 wave for 2m 
and 70 cm; f/ us tier for 10m and other low bands. 



ments and antennas which 
have been found workable. 

Fig. T illustrates the basic 
concept of mobile to base 
station communication via' 
satellite. The uplink and 
downlink frequencies are 
widely separated, yielding, 
without filters, a built-in 
duplex operation. You are, 
therefore, able to hear not, 
only the signals of the station 
you are talking to, but your 
own signals as well - giving a 
continuous indication of how 
well you arc accessing ttie"" 
transponder in the satellite. 

The current OSCAR 6 and 
7 satellites are in approximate 
polar orbits at 900 miles 
above the earth. Both com- 
plete their orbits in about 1 
hour and 55 minutes, ad- 
vancing about 30 degrees of 
west longitude with each 



south to north equator 
crossing. For each overhead 
orbit, they are in good signal 
range of the relatively limited 
capability of simple vehicular 
antennas for about 15 min- 
utes. There will also be 
about 10 minutes of good 
signal strength on the orbits 
two hours before and two 
hours after the overhead pass. 

Thus, for OSCAR 6 and 7, 
there have been three usable 
orbits in the evening lor the 
sou th to north equator 
crossings and three in the 
morning for the north to 
south crossings. This yields 
for both satellites about two 
hours total communication 
time for a 24 hour period. 
The overhead orbits occur 
about 9 am and 9 pm local 
time. There are some varia- 
tions to this pattern which we 
don't need to go into here. A 
vehicular station in the polar 
regions will access the satel- 
lites on every orbit. 

To know what time to use 
the satellites at your location, 
you keep in the vehicle a 
table published by W6PAJ 
showing the ' tfme of the 
equator crossing and the west 
longitude for every orbit for 
every day of the year. To the 
equator crossing time, you 
add the time for the satellite 
to come within range. For 
example, at Albany NY, for 
'an overhead or nearly over- 
head pass, 4 minutes are 
added to the published 
equator crossing time for the 
evening passes and 34 
minutes to the morning 
crossing time. These times, 
from experience, allow the 
satellite to get high enough in 
the sky to be readily 



OSCAR 7 
POLAR OHBiT 
900 MILES LP 



PLJW< -IS? J5 




BASL STATION 



Fig, I. IVIobile to base station operation via satellite. 



40 




Transceiver as in Fig. 3 showing ttie tunable receive converter 
on top of tlie FTWh 



Power amp on 432 as in Fig. 3. There are 2 power supplies — 
12 V dc to 300 V dc and 12 V dc to 1600 V dc - and al2V 
to 115 V ac converter. That's a lot of equipment to generate a 
1 00 Watt plus SSB signal on 432. 150. 



accessible from the car anten- 
nas. 

The conservative range 
over which you can "see" or 
access the OSCAR 6 and 7 
satellites from a vehicle is a 
circle centered on your loca- 
tion about 2000 miles in 
radius. If your location is free 
from obstructions, you will 
be able to hear your own 
signals return from the satel- 
lite at this range and be able 
to communicate with any 
Station having an overlapping 
range during the period of the 
overlap. 

With regard to the mode 
of transmission, the linear 
transponders in the satellites 
will retransmit any mode that 
is offered. To conserve power 
and bandwidth, SSB and CW 
(Morse code) are the pre- 
ferred modes. 

OSCAR 7 Mode B has 
produced outstanding 
vehicular communications. 
Based on calculations by 
Perry Klein of AMSAT, Table 
1 shows the link calculations 
for Mode B using experi- 
mental equipment in my car 
as an example. 

With this brief background 
of how vehicle communica- 
tions are established through 
the OSCAR 6 and 7 satellites, 
we now describe some equip- 
ment arrangements in the 
vehicle which have been used 
successfully. 

In March of 1973, a few 
months after OSCAR 6 was 



launched, the equipment 
shown in Fig. 2 was installed 
in my automobile. For the 
uplink, the equipment con- 
sisted simply of a regular 
amateur type 10 Watt FM 
transceiver, equipped with a 
couple of crystals in the 
uplink passband and arranged 
for keying the driver stages. 
An 80 Watt solid state ampli- 
fier was located in the trunk, 
A standard 5/8 wave base- 
loaded whip was the antenna. 

For the downlink, a 
common amateur band trans- 
ceiver tuned to the downlink 
frequencies around 29.5 MHz 
and a loaded whip cut to this 
frequency did the job very 
well. 

The first use of OSCAR 6 
from a vehicle was made with 
this simple setup. Over a two 



year period of operation on 
the road in various states here 
in the East, it was very effec- 
tive, accounting for hundreds 
of contacts with other ama- 
teur radio operators all over 
the USA and Canada, as well 
as a few contacts with 
Europe. The excitement of 
these early operations with 
OSCAR 6 will be long 
remembered by those who 
participated. This operation 
was all done with a telegraph 
key — not the best mode 
from a moving car. Practically. . 
all operation was, in fact, 
done with the car parked. As 
mentioned previously, this 
type operation was also 
accomplished by several other 
amateurs, using similar equip- 
ment setups readily available 
from suppliers of amateur 
radio equipment. 



During March, 1975, after 
a few months of experience 
with the then new OSCAR 7, 
it became apparent that the 
outstanding signals from the 
IViode B transponder would 
provide a new level of perfor- 
mance from a vehicle. The 
first experiments used a trans- 
ceiver arrangement as shown 
in Fig. 3. 

The uplink starts with the 
same regular amateur band 
transceiver as was previously 
used for receiving OSCAR 6. 
...This is in the front of the car, 
so the transmit frequency 
can be controlled from the 
driver's seat. A low power 
output {1 Watt) available 
from this particular unit is 
cabled to the trunk, and 
connected to a transmitting 
converter (28.150 to 432.15 
MHz' 



Uplink (at 432.150 MHzl 

Transmitter power x antenna gain = EIRP = 100 Watts 
Free space path loss <at 2000 mile range) 
Polarization mismatch (linear on ground, circular at satellite) 
Net nominal receiving antenna gain at spacecraft 

Received signal at Input to spacecraft transponder 

Downlink (at 145.950 MHz) 

Satellite transponder output power (with -109 dBm 

input signal) 
Net nominal transmitting antenna gain at spacecraft 
Free space path loss (at 2000 mile range) 
Net nominal automobile receiver antenna gain 

(including transmission line loss) 
Polarization mismatch (-circular at satellite, linear on ground) 



Received signal at input to automobile receiver 
Receiver noise (bandwidth = 2.4 kHz, noise figure - 
RECEIVED (S+N)/N 



3dB) 



This converter 


+50 dBm 


' -156 dB 


■^3dB 


OdBi 


-109 dBm 


+30 dBm 


OdBi 


-146 dB 


+2dBi 


-3dB 


-11 7 dBm 


-137 dBm 


+20 dB 



Table 1. Note: At a range of 7000 miles (satellite overhead), the (S+N)jN should be 26 to 30 
dB. From these figures It can be seen that very effective communication is possible. 



41 



W3TMZ 



2 N9TR FM | 145.95 MHi- 
XCVH lOW 



^.^J'i^:r - 




-H/f 



^& 






_zrT^i^^z II-- 

ftr '■™ ''■*' * ..'-;---•"■■' 






H^Sr/MZ vv(75 first QSOed from the car via OSCAR 6. The other 
cards are from tiie first fev/ days of operation. 



develops aboui 3 Walls on 
the uplink frequency. A strip- 
line tube type power ampli- 
fier brings this low power up 
to the 100 Watt level. A short 
run of RG-8 cable to a 
ground plane antenna 
mounted on top of a standard 
mobile whip completes the 
uplink cquipmcDt. A rather 
involved power supply was 
required to supply all the 
various voltages required by 
the tube type uplink equip- 
ment in the trunk. 

The downlink receiving 
equipment, since this was to 
be a transceiver installation, 
required a special receiving 
converter to convert the 
145.950 MHz passband 
downlink signals to 28.150 (± 
25 kHz) for the transceiver. 
The crystal in this converter 
had to be on the high side of 
the signal to restore the fre- 
quency inversion created by 
the satellite transponder. The 
crystal also had to be offset 
to adjust for the small fre- 
quency translation irregu- 
larity in the satellite trans- 
ponder and to provide con- 
tinuous tuning to adjust for 
the Dopplcr effect. A crystal 
tuning capacitor equipped 
with a vernier dial was 
employed to facilitate this 
adjustment. The antenna for 
the downlink was the same 
5/8 wave base-loaded whip 
previously used for uplink in 
the OSCAR 6 experiments. 

This array of uplink and 
downlink equipment was 



tested out thoroughly on the 
bench by actually communi- 
cating via the satellite. The 
car installation called for a lot 
of head scratching on equip- 
ment location — particularly 
for the various power 
supplies. 

Murphy must have been 
looking the other way, be- 
cause when I finally tried the 
installation out from my 
driveway on the first available 
orbit, I was rewarded with a 
solid SSB conversation for 
over ten minutes with 
W2BXA in New Jersey. 

Other than a minor prob- 
lem in the high voltage power 
supply, this installation was 
in troublefrec operation for 
more than two years witli 
impressive results. Particu- 
larly on the morning passes, 
when the 7B transponder was 
lightly loaded, the return SSB 
signals were very strong It 
was easy to work European 
stations as well as all of North 
America and the Caribbean. 

Operation in motion is 
quite practicable with no 
observable difference from 
parked. On one occasion, a 
special test was carried out 
where the car was kept in 
continuous motion while the 
mike was kept continuously 
active for an entire orbit. The 
signals from the car were 
copied by many stations all 
over the East and Midwest 
with exceptional clarity. In- 
motion operation does have a 
little problem with two-way 



V 



£ METER UPLINK 
ANTENNA 



V 



10 METER DOffJMLINK 



HIO METER 
ANTENMA 



Fig. 2. Simple equipment for vehicular satellite communica- 
tions. 



/\ 



45.95 -Ay.i 
L53 



REC. 
COW 



23I 5USB hAMBAND 

XCVR 



• 250 "50 ^350 '^leOO 

t t ! t 






1 132-" 

XM'T ] 5-J5S 

CONV I 



> 1 . 5 VAC 



532 r.!Hl flVP 

100 -^i-T 




Fig. 3. Transceiver type equipment used in W2GN mobile for 
SSB communications via OSCAR 7 Mode B. 



contacts due to the need for 
frequent adjustment of the 
receiver to account for the 
Doppler shift. One hand on 
the steering wheel and one on 
the tuning dial leaves the 
mike in midair. 

A 2 meter sideband trans- 
ceiver was next installed to 
supplant the receiving con- 
verter described above. This 
yields the convenience of 
being able to hear your own-- 
downlink signals, an inter- 
esting and important aspect 
of satellite operation. In this 
setup, the transceiver used_to,. 
generate the SSB signal on 
28.150 was installed in the 
trunk, taking ail the clutter 
out of the front of the car. 

A number of successful 
demonstrations were con- 
ducted at various hamfests 
and meetings here in the 
Northeast. The SSB voice 
signals coming down from the 
OSCAR 7 Mode B translator 
invariably gave good loud- 
speaker copy to large groups 
by extending an audio line 
from the car to the meeting 
hall. 

432 MHz SSB transceivers 
and linear amplifiers became 
available during 1975, so we 
continued the .equipment 
saga, and, in early 1976, in- 
stalled a 432 transceiver 
alongside the 144 unit in the 
front of the car and solid 



state linears for both bands 
(2m and 70 cm) in the trunk 
— going whole hog, so to 
speak. 

A regular ham band trans- 
ceiver plus the usual FM unit 
provides a capability for all 
satellite and nearly all regular 
modes of operg.tion on the 
ham bands. The antennas 
continued the same — base- 
loaded whips on 2m and 70 
cm and center-loaded whip 
for ten meter downlink. We 
have come a long way in the 
equipment depaitment since 
OSCAR 6 was launched in 
October of 1972. All of the 
gear mentioned takes up little 
space in the vehicle. The 
availability of satellite com- 
munications has helped to 
stimalate this development. 

As the AMSAT program 
for future satellites unfolds, 
we can expect mobile. opera- 
lion via satellite to be a 
regular part of the day-to-day 
ham operation. Continuous 
coverage via satellite must be 
held as the ultimate goal, 
either through use of high 
altitude satellites or by oper- 
ating several satellites 
properly spaced at a lower 
altitude. 

Once that is accomplished, 
there will be no barrier to 
communication by amateur 
radio from any point on the 
Earth at any time. ■ 



42 



STILL 
UNDER 



$50 




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WE DON'T! 

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FREQUENCY RANGE: All amaWurbands 80 through 10 meters, " TUBES AND SEMICONDUCTORS: 16 tubes, 15 diodes, 7 transistors 

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INPUT POWER: 300 watts PEP, 240 watts CW CVV FILTER KIT $ 46.00 



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Wattmeter 

An inexpensive, in-line 
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output or for monitoring 
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Allow/s selection of wattmeter scales of 0-200 watts or 0-2000 watts. 

Insures consistent, efficient transmitter operation. 

As with all Tempo equipment, the RBF-1 delivers performance value 
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Prices subject to change without noticfl, 

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H3 



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Butler, Missouri 64730 815/679-35 27 



43 



David J. Brown 1V9CGI 
RK 5, Box 39 
Nobiesvills IN 46060 



Tic Tac 
Touchtone 



--a new method ! 



Between the looks of the 
push-button pad 
arrangement of the Touch- 
toneTWl and the hit-and-mi5s 
aiming technique I had been 



running until recently, the 
title seemed a lii<ely one for 
the circuit block diagram in 
Fig. 1. What the circuitry 
allows you to do is tape 



record (or manually enter)"- 
TT tones that are then 
entered into a decoder for a 
one-of-ten number choice. 
These tones are changed. -ta. 



HOLD — 




1— »| R-ELAYS B STO^ LED'i 

' T^r ill 



I 









LATCH 

a 

COMP 




LATCH 




LATCri 

a 

COMP 


„_^-^ 




' 









► cut £H0- 




_ __ i 














O'J-. '■■" 




1 






WI/E5T 




• 1ISE7 






*■ 




- 













=OS-r - N C-iTES 






Fig. J. Block diagram. 



TTL levels, and from one-of- 
ten code to BCD. A set of 
storage latches allows you to 
enter a six-digit riumber 
sequentially, and yet store it 
as six sets of parallel BCD 
data. Now, what can you use 
it for? 

As described, 1 use it to 
record (or enter manually) 
azimuth (3 digits) and eleva- 
tion (3 digits) information on 
convenient cassette audio 
tape for a given OSCAR pass. 
Depending on how you do 
the recording and playback, 
you have enough time on one 
side of a 60-minute cassette 
to record even the longest 24- 
to 28-minute pass in real 
time. At real time, you would 
start your recording with the 
starting position coordinates 
for your antennas, and then 
enter new information from 
your calculated data (or 
Satellabe"'"'^) every one-half 
minute or so, with the tape 
always running. Two draw- 
backs! One, this can eat up a 
lot of tape. Two, it takes as 
long to record every pass as 
the pass really takes! I record 
and play back -mine a bit 
differently. By using a circuit 
very similar to Fig. 7 (R.-S 
flip-flop wired ^tes) to 
control the tape recorder 
run/stop circuit via the micro- 
phone third wire, ! waste no 
tape. You build a second Fig. 
- 7 leaving off Rs, Cs, Rg, Cg, 
and both switches, since the 
tape control inputs will be 
TTL levels. The relay con- 
tacts are then wired as in Fig. 
7(a) to control the tape 
recorder run/stop circuit. For 
inputs to this added IC, refer 
first to Fig. 2. lC5-n shows a 
lead going off to tape. Attach 
this lead to the new IC pin 
13, taking the place of the 
hold switch of Fig. 7 and 
forming the tape stop com- 
mand. Whenever a # is 
decoded from the tape or 
direct command, the tape 
stops. To start the tape, any 
TTL-compatible pulse from 
high to low into pin 9 of the 
new IC will start the tape. 
The relay will close and the 
tape will run. To record using 
this method, Set the pulse 
(from timer or electronic 



A4 



clock at 1 or 2 per minute) 
start the tape on playback, 
and use a momentary low on 
pin 9 to start the tape when 
yoii are ready to enter new 
data for a pass when re- 
cording. You enter your data 
in 6-digit format shown by 
this example for an azimuth 
heading of 163 degrees and 
an elevation of 45 degrees: 
Enter by pushing the TT pad 
buttons 1 , 6, 3, 0, 4, 5, #, for 
a 1 63045^ sequence. When 
you hit the ^ key, the tape 
will stop, but the tone will be 
on the tape. Start the tape 
with H pulse again, and after 2 
10 3 seconds, enter ihe next 
headings, followed again by 
#, and so on. When the timer 
plays back the tape, one 
6-digit number and stop tones 
will be played back for each 
timer pulse, so be sure to 
enter data for every minute if 
a one-per-minute timer is 
used, or data for every one- 
half minute if a 2-pulses-per- 
minute is used, etc. 

The interface shown 
between the IT pad and the 
recorder is a combination of 
the TT pad level control, the 
ALC circuit of the recorder, 
switches you choose to use, 
cables and plugs, and so on. 
Nothing fancy, and not 
included here due to the 
many types of pads and re- 
corders. The same goes for 
the interface shown between 
the recorder and the TT 
decoders in the playback 
mode. It can be any ALC, or 
the recorder playback volume 
control, or anything to hold 
the tone levels to about 50 to 
1 00 mV (if you are using PLL 
decoders). The TT decoders 
are also not shown, as they 
have been in many forms, in 
many magazines. It's your 
choice, just as long as the 
output goes from about +4.5 
V dc to ground on the output 
line when that tone is re- 
ceived. 

Taking it from the output 
of the TT decoders, the high 
and low tone group outputs 
(lows) are fed to an inverter 
so that both high and low are 
available for each output. 
Then the inverted forms are 



fed to gates to decode a single 
number for any tone pair 
received. Output from these 
gates is fed to a 10-line to 
4-line converter IC. This 
741 47 IC happens to accept a 
low on the G to 9 input line 
side, and outputs BCD code 
equivalents of the digit that 
was entered. This inversion 
doesn't bother us, as the BCD 
is inverted again in the 7475 
latches by using the Q 
outputs. The then BCD code 
is fed to a 7485 comparator 
IC to compare it with the 
BCD code sent down from 
the antennas. That covers the 
signal path, which is really 
easy. Now for the controlling 
part! 

Going to Fig. 3, all lines 
that enter each half of IC17 
are normally high during no 
tone. When any valid TT 
tones are received, one input 
line of one half of 1C17 (pin 
1, 2, 4, or 5) and one input 
line of the other half of 1C1 7 
(pin 9, 10, 12, or 13) will go 
low (for the numbers to 9, 
but more on that later). Since 
lC17isa7420 4-irjputNAND 
gate, all 4 lines of either half 
input must be high for a low 
output. When the tones cause 
these IC17 outputs to go 
high, IC28-3 goes low. This 
causes the one-shot IC18 to 
fire for approximately 5 ms. 



The one-shot IC18 output 
enables half of IC19 and 
1C20, 7408, and gates. The 
other haif of only one of 
these gates at a time is 
enabled by what line (U, V, 
W, X, Y, Z) is also high. If we 
are in the tirst digit position, 
for example, the counter 
7490 (1C15) and decoder 
7442 (I CI 4) would be in the 
zero (reset — 1st digit) posi- 
tion. IC14-1 will be low, and 
when inverted by 1C13-1 to 
ICl 3-2, a high results, 
enabling IC19-3 to a high. 
This high turns on the iatch 
enable line of IC7-4 and 
IC7-13. The BCD data for the 
first digit present on the 
common BCD bus in Fig. 2 
are transferred to the output 
side of only that latch. It is 
then compared by the 7485 
(1C21) with the current 
antenna BCD read down to 
the other side of the 7485. 

Going back to Fig. 3, the 
same low for a valid TT tone 
at IC28-3 that keyed the 
one-shot ICl 8 is also fed to 
ICl 6-1 2 and 1C1 6-1 3, causing 
a high at ICl 6-11 and 
ICl 5-1 4. This low to high 
transition when tones are 
received does nothing at the 
counter input ICl 5-1 4; how- 
ever, when the tones stop, the 
condition reverses (high to 
low}, and the counter ad- 



vances one position and is 
ready for the next number. 
You can follow through the 
counter (ICl 5) and decoder 
(1C14) up through ICl 4-2 to 
ICl 3-1 to IC13-4 to 1C19-5, 
and see that the next position 
is then half enabled and needs 
only the one-shot pulse from 
ICl 8 when the next tones 
come along to load the 
second position latch (IC8) 
with second digit BCD data. 

It should be noted at this 
time that the TT pad * key 
can be used to reset the 
counter and latch positions. 
1C1 6-4 and ICl 6-5 are used in 
upside-down gate fashion, 
much like IC28-1 and 1C28-2, 
in that if either high goes 
away from the inputs, the 
output goes high and resets 
the counter. ICl 6-5 is also 
used to reset the counter 
when position "6" is reached 
in the 7442, so the counter 
does not rely on the * to 
reset. The position "6" reset 
is detected as a BCD 6 by 
ICl 6-1 and 1C16-2 to ICl 6-3 
to ICl 5-5. 

Refeiring to Fig. 3 and 
ICl 7; The inputs to these 
gates were originally wired to 
detect all valid TT pairs, but 
this leads to both limited and 
confusing control. _By using 



^" 



->^ 



-o- 



->■ 



4>- 



->>- 








^ l_ 






;i 


7 


ICi-S 


14 


7 


T*i«T 


^ 


B 




I 


'■ 










Fig. 2. Decode and store diagram. 



45 




IC ff 

13 

14 

15 

16 

17 

IS 

19 

20 



Name 

7406 

7442 

7490 

74O0 

7420 

74121 

7408 

7408 



Vcc 

14 
16 
5 
14 
14 
14 
14 
14 



Gnd 

7 

8 

1 0-6-7 

7 

7 

7 

7 

7 



/v^. 3. Control unit. 



pin 5 wired to -i-5 V dc 
instead of H4 where it was, 
we delete tfie decoding of t lie 
entire H4 group (A, B,C,and 
D letters on some TT pads). 
This allows their detection by 
NAND gates wired like IC3, 
4j and 5, without causing any 
counter or iatch action. After 
all, you never want to enter 
this as data- to the number 
latch anyway, but you may 
want them for tape or local 
control signals (future use!). 
Also, in the low tone 
group inputs, a gate is added 
to the L4 input. By doing so, 
we set up the low tone half of 
ICl 7 to only recognise of 
the L4 group (*, 0, #, D) as a 
valid number to be loaded 
into a latch when received. 



This occurs when the tone 
pair for zero (H2 and L4) are 
inverted in IC2 and appear as 
H2 at IC16-9 and L4 at 
ICl 6-10 as highs. This causes 
a low at ICl 6-8 and a high at 
ICl 7-6, and with both 
outputs of ICl 7 high, a valid 
number is "seen" for loading 
the latch. 

Both * and #are L4 tone 
numbers, but neither has the 
H2 high tone, so they both 
are ignored by ICl 7. Thus, by 
wiring the ICl 7 high group 
correctly, and adding a simple 
gate to the low tone group, 
only the numbers to 9 are 
used to load the latches. 

I believe that covers the 
line by line, so let's examine 



the 163045 example given 
earlier, as it progresses 
through the digital hardware. 
The 1, of course, was de- 
coded and stored in latch 
IC7. Then the 6 is put in, 
decoded, and stored in latch 
iC8, the 3 is put in latch IC9, 
the in latch ICIO, the 4 in 
latch ICl 1 , and the 5 in latch 
ICl 2. Going to Fig. 4, you 
can see by the "numbers" 
shown in iCs 7 through 1 2 
just what is stored where. 

If the relay power is in the 
automatic rotate mode of 
Fig. 7, IC2S, then the anten- 
nas will begin to move the 
instant the first digit Is re- 
ceived, decoded, and latched, 
if it differs from the antenna 
position in that digit. Fig. 4 
also shows the output relay 
control lines of the 7485s 
under "other 7485 connec- 
tions." The 74-85 has cascade 
inputs available at pins 2, 3, 
and 4, and these pins are 
used. The overall output of 
the 7485s seen by IC27, pins 
1,3, and 5 for azimuth, and 9, 
11, and 13 for elevation, can 
be in only one state at a time 
- either A > B, A = B, or A 
< B. These overall outputs 
are in whatever state the 100 
IC21 commands until A = B 
in that IC. IC22 then take^ 
over, followed by IC23 
(azimuth example). For 
instance, if we started the 
beams mechanically at 000 _ 
degrees (north) for azimuth, 
and 000 degrees elevation, 
the following would take 
place after the data was all in 
and stored (163045), and 
then the relay power applied 
with the "auto-rotate" 
button: 1C21 says A > B, 
output A > B, and the CW 
relay pulls in to increase 
degrees azimuth on beams 
(increase B data) until 100 
degrees is reached and rC21 
says A = B in this digit. Then 
IC22 takes over with its own 
A > B, output A > B, and the 
CW relay stays in until 160 
degrees is reached and 1C22 
says A = B in that digit. Then 
IC23 takes over with its own 
A > B, output A > B, the CW 
relay stays in until 163 
degrees is reached and IC23 
says A = B, the azimuth stop 



LED comes on, and the CW 
relay drops out. 

The same thing happens 
independently in IC24, IC25, 
and 1C26 for elevation. In our 
example, IC24 immediately 
sees an A = B (0 = 0) and 
transfers control to IC25 
until 40 degrees elevation is 
reached and an A = B con- 
dition is reached in IC25. 
Then IC26 takes over with an 
A > B command until 45 
degrees is reached when the 
up relay (energized until now 
and driving the beams up- 
ward) drops out and the 
elevation stop LED light 
comes on. The system is then 
at rest, and remains so until 
further data streams are re- 
ceived from the tape-timer or 
by manual entry. 

While on the subject of the 
relays, Fig, 7 was added so 
that data commands could be 
entered when in the hold (no 
relay power) mode without 
actually turning on the anten- 
nas. It is a handy override, 
because if you want to stop 
the antennas at any time, you 
can do so with a push on the 
"hold" button. ^Hitting the 
"auto-rotate" button returns 
control to the latches of the 
TT controller system. This 
-. also means that you can 
cancel a taped command by 
overriding it with the hold 
button, enter a mmiuai com- 
.mand, and return to auto- 
matic by pushing the auto- 
rotate button. 

I included a panel layout 
(Fig. 6) to give you a starting 
point. Laid out this way, it is 
funcrtonal and not confusing. 
I used orange plexiglas over 
the BEAM 7 segment 
displays, and ruby red in 
front of the DATA entered 
readouts to avoid mix-ups. 
The hold LED is red, the 
auto-rotate green, and (in my 
case) the CW, CCW, Dn, and 
Up LEDs are all yellow. The 
3.Z and el stop LEDs are, of 
course, red. The panel is gray, 
with black TT keys with 
white lettering, so it makes a 
nice addition to my Drake 
equipment. In fact, I used a 
Drake speaker cabinet (IVIS-4) 
and had tons of room left 
over, both on the panel and 



46 



in the box. 

This system replaces the 
earlier Autotrak* at my QTH, 
but to each his own. If 
you have the RTTY gear, the 
earlier system was okay, but 
required a lot of hardware to 
get from Baudot to BCD and 
the like just to have the ad- 
vantage of pre-stored tape 
(paper tape in that case}. The 
advantages of this newer 
system override any draw- 
backs of not having a hard 
copy printout, and careful 
labeling of the cassettes 
should eliminate any prob- 
lems. 

With the average OSCAR 
antenna setup, having tapes 
for every 5 degrees of longi- 
tude seems to be more than 
adequate, amounting to some 
15 to 20 pass combinations, 
worst case. All this fits nicely 
on 2 cassettes in my non-real 
time system. You can get 
sneaky as you record by using 
a pass "code" information 
right on the tapes. Let me 
show you by example. Since 
azimuth information is the 
closest to longitude or surface 
information^ I chose to use 
those readouts to locate a 
point on a tape containir^g 
some 4 to 6 passes. When 
recording, ahead of each 
sequence of pass information 
enter the following "code": 



*"l ntroducing Autotrak!", 
W9CGI,73,Julv, 1977. 

RELAY DETAIL 



CCINN FOB T SEG 
DECODERS 




Fig. 5. Si = silicon diode, 50 
V, TOO mA. All RL chosen 
for LED used. 




OTHER 7485 COWMECTIONS [RELAY CONTROL) 



^5V 

16 a'^O 



Aj 



azioo 



T" 



~ 



INPUTS 
FROM BCD 

WHEELS AT 
ANTENMAS 




■c>- 



^t^.^^ 



-!>- 



^9LY 

+ V 

A.'. -STOP 



ELEVAflOf^ 
READS 0-90*' 
AND THE RIGHT 

ON OVER TOP 
WITH 90" = lOD" 
70^= 110" 
60" ^ 120* 
[SEE TEXT] 



/ 

SEE FIG 5 
RELAY DETAIL 



A 3 C [J 



Push *,then whichever of the 
A through D keys you want 
to use for this function, then 
the longitude of the equator 
crossing for that pass you are 
about to enter next as a 3 
digit number, then 0, then 0, 
then 0, then the A to D key 
you chose above again, then 
wait 10 seconds, then push 
the * key to clear the register 
(counter), then wait 5 
seconds, then begin entering 
your data for the pass as 
shown before. 

By opening the antenna 
circuit with the hold key, and 
defeating the tape stop com- 
mand by closing the defeat 
switch in Fig. 7, you can go 
down about 30 minutes 
ahead of the pass. While 
letting the gear warm up 
[please!], you begin playing 
the proper tape back. Ex- 
ampSe: An overhead pass for 
me is 72 degrees crossing at 
the equator, so 1 take my 52 
degree to 77 degree tape (I go 
in 5 degree increments on 
either side of an overhead 
pass here) and put it on the 
recorder. The pass I am look- 
ing for is the fifth one on this 
tape. When the tape begins 
playing back, the first jnfor- 



Fig. 4. TT controller. 

mation I get is a *, to clear 
the counter to position one 
regardless of where it came 
on when power was applied. 
Then the D tone is in my case 
decoded and wired into an 
audio monitor (NE555sand3 
speaker) to form a 1000 Hz 
warning tone that in this case 
means that longitude infor- 
mation is about to be 
presented on the data read-- 
outs. Next, the tape decodes 
and displays the digits 052 
000 on the data readouts, 
telling me that the informa- 
tion that follows is for a pass 
having a 52 degree equator 
crossing. The audio warning is 
repeated. Then the decoded * 
clears the data counter to the 



1st position (it should be 
there due to a detected 6th 
digit position after the last 
was entered — but why risk 
it?). The information that 
follows is pass data, and the # 
does not shut off the tape, 
since you defeated Chat 
circuit. When the tape reaches 
the next "code" information, 
the above is repeated (in my 
■case: clear, tone, 057000, 
tone, clear), so that you stop 
Che tape manually right after 
the equator crossing you 
want (072000). You would 
Chen push the defeat switch 
to normal and the auto-rotate 
button, and set up your timer 
Co control tape starts. For the 
exact time of the crossing, I 



HHHH 
HHHH 
HHHH 







AZ 








EL 






( 1 


l~ 


-r 




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l~l 


> i\ 




I'-l 


/_l 


u 




u 


LI 


ri 




® ® ® 




@ @ @ Jl 


LOAD DATA LOAD tl 






BEAM 


II 




'q 


i~ 


1 '1 


® ® 


'rn 


,Q 


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C® ©} 




®i f® 


OEC INC OEG ING 



HOLO@ 



v_ 



(Q) 



Fig. 6. 



47 



> w^ 







Fig. 7(a). 



enter the approximate 
azimuth from the Satel- 
labeTWi^ and an elevation of 
000 degrees. Two reasons: 
One, 1 can start all runs with 
the published crossing time, 
even though the satellite is 
out of range — it is not 
always out of range! Two, 
this gets the antennas into 
approximate position for 
your AOS position anyway, 
so you don't have to wait on 
them coming around. I use an 
automatic calf sender that 
keys off the same high to low 
transition from the timer that 



starts the tape, so I listen for 
myself even before normal 
AOS and then turn off the 
sender. This all makes every 
pass a very repeatable situa- 
tion — they all start at the 
equator, and the first tape 
information is for equator 
plus 30 seconds. I run the 
beams around to the equator 
start point with a manual 
entry from the keyboard, just 
before doing the timer setup. 
This way, I have one manual 
function to do concerning the 
antennas when the satellite 
crosses the equator — pushing 



Fig. 7(b). 

the "go" button on the timer 
to start the fiist thirty second 
period. Thirty seconds later, 
the timer sends a pulse to the 
controller - tape start — and 
the T + 30 data is read in and 
the beams run to that posi- 
tion. At 40 degrees latitude, 
this is always the same as 
what you manually loaded, so 
you could include it on the 
tape and let the tape read in 
the initial condition by turn- 
ing the normal defeat switch 
from defeat to normal {after 
the longitude figures you 
want are read and clear them- 
selves, but before the first 
data coordinates arc picked 
up off the tape - we left 
about 5 seconds). This- way, 
the decoder picks up the first 



tape stop #, and would wait 
there until the timer T + 30 
pulse - putting you right 
back in sync. 

That sums up the theory 
and the how-to-tape informa- 
tion part. It works great, and 
allows me to concentrate on 
the receiver instead of grow- 
ing a third hand for the 
antennas. No doubt you will 
find your own uses and prob- 
ably some variations, and 
that's good — write them up! 
1 have no beef with anyone 
who starts with my idea and 
improves on it — chances are 
I'll add it to my system, too. 

Please include an SASE if 
you need help. The letter 
load has increased with the 
increase in my "articles pub- 
lished" count, bur same day 
answers are usually still 
possible if you make your 
questions clear and concise. 
Adaptations and modifica- 
tions by you take a whiie 
longer, since I like to try 
what you did on the hard- 
ware here and see what reaily 
happens. ■ 



' -t 



r >"•<■■ ) i '■■■ 










from page 1$ 

of '76. In January '77. I flunked my 
first time on the General, but then 
went in February and passed it. Then 
3 months later (Mav), I passed my 
Advanced; 2 weeks later in June, and 
during ihe last vjeek of school, with 
all the final exams, yea, I Vv-alked away 
with the Extra on my first try. Same 
day I sent away for my 1x2 call. 
Youngest ham to get (or have) a 1 x 2 
catl? 

I guess if you show this tetter to 
some of your local CBers, it'll get 'em 
off their tails and show 'em how easy 
it is. 

How did I do it? Naw, I'm not a 
"child prodi(jy" and my marks in 
school aren't too good. It took a lot 
of time and energy and staying away 
from all the wild women. And if you 
wanna speak to me, I'll probably be 
on the bottom of 20 meters CW (or 
where I am now, relegated to 2 meter 
FM with a borrowed HT because of 
antenna problems). And I'll talk to 



anyone. 



Howie Goldstein ^VB2iWX 
Brooklyn NY 



PLUGGED IN 



Right on. Hark Clark WB4CSK, 
"Letters," September issue of 73! 

Through studying and a conscien- 
tious effort, I earned my license 
(Advanced). Because of that, I have a 
certain sense of accomplishment and 
pride in being part of the fraternity of 
ham radio. Also, because of that, I 
would not knowingly do anything to 
jeopardize its existence. 

For those who subscribe to the 
quantity theorem for getting new- 
comers into ham radio, I propose that 
you listen to Ch. 19 CB for a couple 
of days, then ask yourself, "Do I v/ant 
to listen to that on the ham bands?" 
There are too many appliar^ce oper- 
ators in our ranks as it Is now. 

For those existing amateurs who 
believe in easier upgrade privileges. 



Sake another look. Maybe you are one 
of those appliance operators. 

Richard L. Miller WA40ET 
Ft. Belvoir VA-- 



UPDATE 



We were indeed happy to see youn ■ 
three-page coverage of TEN-TEC 
modificalions to the Argonaut in the 
August, 1977, issue of 73. The only 
problerii that wa see is that it was not 
pointed out anywhere in the anicle 
that the modifications described were 
performed on our old Model 505 
Argonaut, which was replaced in June 
of 1975 with the Model 509, The 
IWodel 509 indeed incorporates the 
modifications shown in the article 
with the exception of the disconnect 
socket on the speaker. The reverse 
polarity protection and the drive con- 
trol on the front panel are incorpo- 
rated in the E\/lDdel 509 and always 
have been. I would appreciate it if you 
would run this information in your 
letters column so that owners of the 
Model 509 do not feel that modifica 
tions are desired or necessary with 
their units. 

The only statement in the article 
that WE take exception to is the one 
where it is intimated that TEN-TEC 
had a prepackaged kit of parts for 
repairs to units that were connected 
up reverse polarity. I know of no such 
prepackaged kit, but the usual damage 
was to the switching transistors on the 



control board, and possibly the large 
electrolytic capacitor across the dc 
line. 

TEN-TEC, Inc. 

Daniel J. Tomcik 

Executive Vice-President 

Sevierville TN 



GUD QSO, OM 



Most hams have listened to some- 
thing like this: "We are a doctor here 
and have a patient due in our office in 
ten minutes, so we will have to say 73 
for now," etc. 

I have been a ham for over 25 years 
and have heard "we" used to denote a 

Continued on page 75 




48 




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Weight: 25 lbs. 
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DIVISION OF BROWNIAN ELECTRONICS CORP. 



Export prices are slightly higher. Prices subject to change. 



BOX S / 320 WATER ST. 
Phone 607-723-9574 



BINGHAMTON, N.Y. 13901 
V5 



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'master charge] 

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Michael J. Di Julio V/B2BWJ 
97 Woodside Road 
Maplewood NJ 07O4O 



A 



Visual 
OSCAR Finder 



" nice side effects! 



very unique OSCAR- in QST in May, 1974, de- sistecl of a rotating globe with 
locating aid appeared scribed by VVi^CY. It con- several LEDs around it, se- 




Completed OSCAR finder. 



quentially turning on and off 
to simulate the position of 
OSCAR. The project used 
several gearing arrangements, 
entirely too many LEDs, and 
a nS-position rotary switch 
to accomplish its task. I felt 
this to be too costly 2nd 
mechanically complicated, 
and I was prompted to sim- 
plify this otherwise excellent 
article. 

The only mechanical 
device in my locator is a 
24-hour clock movement, 
obtained from a Master 
Grafters 24-hour world clock. 
This clock was popular with 
hams in the 1960s and can be 
found at hamfest flea 
markets. Mine had been 
retired years ago, when I built 
a digital station clock. The 
movement and all hands are 
removed from the clock, and 
the back cover is removed 
from the movement to 
expose the gears. For this 
project, it is necessary to 
reverse the rotation of the 
clock. The motor will go in 
any direction in which it is 
started, but there is a ratchet 
underneath the ,on!y yellow 
nylon gear in the movement 
that foices the clock to turn 
clockwise. This ratchet is 
removed by drilling out the 
rivet holding it. Now the 
clock will turn in any direc- 
tion in which it is "Started. 

The giobe used was bought 
in a five-and-ten-cent store, 
and it is made by the Ohio 
Art Co. It was originally 
intended to be a bank, so the 
base on it must be removed. 
This fs easily accomplished by 
pulling the base straight out 
from the. globe. Next, a 14" 
hole is drilled in the south 
pole, and the outer ring, 
salvaged from the hour hand, 
is soldered to the globe at the 
south pole, after removing 
the paint from the globe and 
the ring at the point of 
attachment. The globe will 
now fit snugly on the outer 
shaft of the movement, as the 
hour hand did. On the globe, 
a 2500-mi!e-radius circle, 
drawn to scale, is centered 
around your QTH and drawn 
with a marking pen. This 
indicates the area within 



50 



Parts List 
ICs 

1 7493 Ufayette 32P06919V 

1 74154 Radio Shack 276-1834 
3 NE555 Radio Shack 276-1723 

Resistors 

3 10k y^ Watt 10% all Radio Shack 271-1300 

2 Ik /4 Watt 10% 

1 2,2k 'A Watt 10% 
1 1 meg '-k Wat: 10% 

1 6Sk K Watt 10% 
1 360 K Watt 1 0% 
1 Ik KWatt 10% Radio Shack 271-000 

1 10k 10-turn trimmer pot R1 

Capacitors 

2 0.01 uF disc ceramic: one at 200 V Radio Shack 272-131 and one at 

25 V R ad 50 Shack 272-131 
1 3200 uF 6 V electrolytic Radio Shack 272-1021 
1 3200 uF 10 V electrolytic (can be smaller — see textl Radio Shack 

272-1021 Ct 
1 1 uF 5 V electrolytic Radio Shack 272-1406 
1 10 uF 10 V electrolytic Radio Shack 272-1002 
1 0.05 25 V disc ceramic Radio Shack 272-134 

Other Semiconductors 

16 LEDs miniature or subminiature Radio Shack 276-042 

4 H\I4001 Radio Shack 276-1 101 
1 2N3906 Radio Shack 276-2021 

1 5.1 V 1 Watt zener 1M4733A Lafayette 32P08691 V 

Miscellaneous 

1 8 Ohm miniature speaker Lafayette 99PB0360V 

1 SPST svA/itch Radio Shack 275-612 

1 normally-open push-button Radio Shack 275-1547 

1 117 V to 6.3 V transformer 300 mA Radio Shack 273-1384 



!0V 



which the satellite may be 
worked. 

The 16 LEDs are soldered 
to i piece of bus wire shaped 
in a 5" diameter ring, to 
simulate ihe satellite's orbit. 
Separate wires are run from 
the cathodes to the appro- 
priate pin on the 74154 chip. 
Small pieces of plastic tubing 
are used between the LEDs, 
covering the bus wire and 
connecting wires. The LEDs 
are spaced so that one is 
placed at each of the poles 
and at the equator on both 
sides, and three are evenly 
spaced between each of these. 
The ring is held to the cabinet 
with a cable clamp and 
adjusted to an angle of 102 
degrees for the OSCAR 6 
orbit. 

A 555 timer chip is con- 
nected for astable operation 
with a period of 431 seconds 
(114.9946 min./16). The 
exact time is set by adjusting 
the 10k 10-turn pot, which is 
in series with the 68k resistor. 
The output from this clock 
goes to the input of a 7493 
BCD counter. This device 
gives the appropriate 4-bit 
BCD code for the rrumber of 



transitions that occur on pin 
14. After reaching 16 counts, 
the counter resets to the 
0000 state. There is also pro- 
vision for externaity resetting 
the counter for setting the 
device up initially. 

The four lines from the 




NO. EQU/xrOR RESET 



501".; 



BEEPER 


lOV 

11 ^ 


h |a 


^ 


IK 

tKH; 




ON^OFF 


' '>';^> 








'l 






E 


lOK 




PEAKER 




L. 




\\ 






f}} 




^U 


-^ 






Fig. L 









7493 drive the inputs of a. 
74154 4-to-16-!ine decoder. 
This device has four lines in 



and sixteen lines out. All 
outputs except one arc nor- 
mally high. The output that 




Suggested parts placement for OSCA R finder 



51 



PC boards are available from the author for 
S6.00 plus $1.00 for postage and handling. 



-5;;g>s ^ OSCAR +y ^8oo 

ft^^ W; — f FIND ER V£^ 



U 

+ 




TO 6. 3 VAC XFMR 



O 



3200/iF 
10 V 



^\^ 



JGBK 



■i 



10 K 
POT 



'IM 



lOK 



Jl NO. 

RESET 



r-^ 



JUMPER 



lOK 



T 



l^iF 




■V, 2.2K 



8 



O 



o 



I 360 

TO ANODES OF LED'S 

Fig. 2. PC board. 



goes low is the one whose the four lines in are 1010, the directly drive the appropriate 
BCD code has been addressed tenth output goes low (pin LEDs through a current- 
at the input. For example, if 11). These output lines limiting resistor. 



LED number one is placed 
at the equator going north, 
and the other LEDs follow it 
sequentially. To make the 
LEDs more visible, they are 
made to blink on and off. 
This is done by driving the 
strobe inputs of the 74154 
with another 555 astable set 
at about 1 Hz. When LED 
number one comes on, it 
turns the 2N3906 transistor 
on, which, in turn, activates a 
third 555 astable which oscil- 
lates at about 1 kH^. This 
chip drives a small 8-Ohm 
speaker, when the LE D at the 
equator is on, with a beeping 
tone. This alerts the operator 
that the satellite is entering 
the Northern Hemisphere. A 
switch is provided to turn the 
beeper off, if it becomes 
annoying. 

The power supply is con- 
ventional and adequate, and 
it should be noted that one 
does not really need a 3200 
uF filter capacitor. ! used it 
because I had an extra one in 
the junk box. Use one large 
enough to give a clean tone, 
free from hum, in the loud- 
speaker. 

I found the accuracy of 
the 555 timer used as a clock 
entirely adequate. However, 
greater accuracy can be ob- 
tained by using a smaller 
capacitor of the tantalum or 
polycarbonate variety and 
using a larger value precision 
resistor. This might buy some 
thermal accuracy, but, within 
the box, we find a thermal 
equilibrium, due to the heat 
produced by the clock motor, 
transformer, and chips. As 
long as the shack's tempera- 
ture doesn't change too 
drastically, the clock averages 
quite well. For the real per- 
fectionist, I suggest a crystal 
oscillator with an appropriate 
divider chain. 

To align the unit, the 10k 
pot must first be set so that 
the period of the clock 
astable is 431 seconds. This is 
a somewhat lengthy process, 
but it must be done as accu- 
rately as possible to insure 
correct tracking of the 
satellite. Allow the unit to 
thermally stabilize itself 
before finalizing the adjust- 



52 



merit. 

To set the satellite's posi- 
tion, the following should be 
done. Use an OSCAR locator 
or similar device to determine 
an equator crossing on the 
day that you are setting the 
OSCAR finder. Determine 
the local time of the crossing 
and the degrees of longitude. 
Remove the globe, and ob- 
serve if the second-hand shaft 
is turning counterclockwise. 
If it isn't, take a pair of 
needle-nose pliers and force 
the shaft to turn counter- 



clockwise. Replace the globe, 
and set the globe by turning 
the time-setting knob until 
the number one LED is at the 
correct crossing point on the 
equator. This globe is 
marked at every 15 degrees of 
longitude, so it is easy to 
estimate the correct point. 
Press the zero-degree start 
button, and wait until the 
beeping stops. At this instant, 
press the reset button again. 
This will insure that a com- 
plete cycle is started. Re- 
adjust the globe so that the 



LED lines up with the 
crossing point. One must use 
good timing to insure that 
this process can be completed 
by the time that the pass is to 
occur. 

Periodically check the 
accuracy of the OSCAR 
finder with an OSCAR 
locator or similar device, and 
recalibrate it by turning the 
globe, if necessary. 

Whenever an LED appears 
within the circle on the globe, 
OSCAR is within range. 
Although designed for 



OSCAR 6, the OSCAR finder 
can be used with any sateMite 
by adjusting three things: 
angle of orbit, period of 
orbit, and radius of circle on 
giobe, which is related to the 
altitude of orbit, which is 
related to the period. Finally, 
any 24-hour movement or 
globe that is available can be 
used, and most of the other 
parts are readily available, as 
listed in the parts list, from 
local stores as wel! as from 
the maii-order houses. Good 
iuck on OSCAR hunting! ■ 



FCC 



Oscar Orbits. 



Before the 

FEDERAL COMIVlUNlCATlONS 

COMMISSION 

Washington, D.C. 20554 

In the matter of 

Dismissal of six Petitions 
for Rulemaking in the 
Amateur Radio Service 

RM-1455, RIVI-1536, 
RIVI-1703, RM-ZOSO, 
RM-2797, RIVI-2907 

ORDER 
Adopted: August 24, 1977 
Released: August 26, 1977 

1. The Ccmmission, by its Chief, Safety 
and Scecial Radio Services Bureau, acting 
under delegated aLithority. has ur.d&r coti- 
sidera:.Dn S:he six pe"!tior\s fo:' rulen^aking 
listed aboye, eacli of wlijcl"* vJai submitted in 
accordance with the Adrninsstrative Pro- 
cedure Act, 5 use G53{e), and Section 
1 .^01 of the Commjssion's Rules. The 
petitions we are considering each requ&st 
i;erlain changes in the Commission's rules or 
policies governing the iss^igninent of station 
epllsigni in the Arnateur Radio Service. 
Peiilioners' spacftic reriLj<ists are as folJows: 

a. RM-1455. V:. Wayrs Green 
requests aTierdrnent zii Section S7.53 
o* the Rules to penrit a licensee 
moving fronri ore callsign area to 
another to obtain a "co jnt^rpart" 
callsicn uDon rnodlfjcation of hi& 
siai.on license. {A "counterpart" calJ- 
sign is a callsigr^ wiih a SLi7fi>i identical 
to the sLffix of s callfiign held Jn 
another callsign area.) 

b. RM-1536. The American Radio 
Relay League, Incorporated (ARRL), 
also requests that provisions be made 
in the rules tor the issuance of 
"counterpart" caUsigris, 

c. RM-U03. Mr. Thomas V, 
App er as.ks for revision of Sectior. 
97.5 T of the R j ts "o s^rmi^ the 
assignment of a 5pe:;itic jnassignjd 
cail^ian to the v*'idcvj. son, or daughter 
of a deceased formei' holder of that 
specrfic callsign. 

d. HM-2Oa0.\fr Chester L.Snith. 
Mr. Joseph Sants.ngeio, IVV. Charies A. 
'.■Valbridge, and Mr. Donald A. Fre&- 
land want the Commi^^ion to amend 
rTS rules to permii ttvs issuance of 
callsigns containing a special indicator 
designating the oper^tnf Ncgnse classi- 
fication of the staiion licensee. 



e. RM-2797. Mr. Cliff Ryan re 
quests that the Commission issue 
station callsjgrs with a specie! c-^sig 
na^or to indicate the state in which the 
sl5tton i^ located. 

f. R!A-2907, Mr. Robert E. 3abb 
requests the 'Liie^ tis amended to 
permit the issuance of so-C3iled "one 
letter" callsigns \i\ the Amateur Ssr- 
vice. (A "one letser" callsign is a 
callsign consisting of one letter, fol- 
lov/ed by one number, followed by 
one letter.) 

2. We have futly aiid carefully analysed 
petitioners' requests and have concluded 
that petitioners' proposals have been and are 
being considered in connection with other 
rixtemaking proceedings. With respect to 
each of these pe' lion^, we note That In 
docket 31135, Ni^iicc of Proposed Rule- 
makirg released P^larch n, 1977, 42 Fed. 
Reg. 15433 11977), the Commission 
pmpos3d to simplify its amateur station 
callsign regulations by replacing the existing 
complex ru'esv/ith a very simple genera! ruie 
stating that all callsigns shall be assigned by 
the Commission on a sysiemgtjc basis. The 
Commission's proposals in Docket 21135 
would, if adopted, preclude granting any of 
the petitions under consideration, each ol 
which requests the issuance of special 
format, non-systematically assigned callsigns, 
In connection v/ith flM-1703, we would atso 
note that the Commission explicitly con- 
sidered the question of "iri memoriaiTi" 
callsigns in lt5 First Report a.nd O'der in 
Docket 20C92. FCC 7634B. released April 
2% 1976. in that Report and Order, the 
Commission aliminaied the ayailabihty of 
"in memoriam" callsigns. (Such calisigns had 
preu;ojsly b&en av^i able to qualified ama- 
tsjr cljbs end organiz^tions.i Fjnalfy, we 
wouid observe tnGl the suggestions con- 
tained in RM-2080 were considered, and 
rejected, in Docket 1 5928, Report end 
Ordei adopted August 24, 1967, FCC 
67-978. 

3. From the forefloing, it is clear that Th$ 
factors on which petitioners' proposals art; 
based have been and are being fully con- 
sidered by tlie Commission in connection 
with other ruiema^ing proceedings, Further, 
pet tioners- have not advanced any new cr 
novel arguments warranting additional con- 
sideration. 

4. Accordingly, the Commission 
ORDERS, by its Chief, Safety. anc S"e::iel 
Radio Services Bureau, acting under di. 
thooty deisgated to h^m by Section 0.331 of 
the Commission's Rules, that RP.'1-1455, 
RM-1536, Rlv:-1703. RM-2080. RM-2707. 
and RM 2907 ARE DISMISSED. 

Charles A. HFgginbotham 

Chwf, Safety and Special 

Radio Services Bureaii 





Gicat 


J 0;biI3i infonnatior. 




dii 


jr 7 Oibilal Inhimalio 


n 


Orbit 


OaK 


Tine 


l-oi:]iljde 


Bib[| 


Bal? 


T7fne 


Lj3ngilud£ 






(Nov! 


IGMTl 


.IE,. 
Crocirg v.' 




I»ii/i 


(Em; 


ol Eq. 


>JA 


33071 .BIN 


1 


01«:-!6 


91 2 


13547 A 




0103:39 


;j.u 


■\]A 


?30a3BTN 


2 


0047.42 


76 2 


13560 BX 


3 


0164:56 


33 6 


^i 


23095 


3 


0142:38 


89,9 


13572 A 


a 


0054: 1 7 


63 5 


'■iA 


23iQ3BT!< 


■I 


0043.34 


74 9 


13665 B 


4 


CI 43:34 


82 ■ 


ij 


23;2i 


5 


0137-39 


88.7 


13527 A 


f: 


0047:56 


06.9 


IJA 


23133 BTN 


6 


0037 3.S 


73.7 


13510 6 


3 


0143:13 


S0.5 


N 


23146 


7 


0132:21 


av.5 


13S22A 


7 


0041:33 


65,3 


,\iA 


23168 BTN 


8 


0032:17 


73.5 


13635 B 


B 


0135:50 


78,9 


KA 


23171 BTN 


9 


0127:12 


BS.2 


13647 AX 


9 


0035:10 


63.8 


N 


23183 


10 


0027:08 


71.2 ■ 


13660 B 


10 


0129:28 


77.3 


NA 


23196 BTN 


11 


0122:04 


85.0 


13672 A 


11 


0028:48 


63.3 


N 


23203 


12 


0022:00 


70.0 


13685 B 


12 


0123:05 


7S.3 


NA 


23221 aTN 


13 


0116:53 


S3. 7 


13697 A 


13 


0022:25 


60,5 


N 


23233 


14 


0016:51 


ea.7 


13710 BQ 


14 


0116:43 


742 


NA 


23346 alN 


15 


□1 1 1.47 


S2.5 


13722 A 


15 


0016;04 


69 1 


K.A 


23258 3TN 


■A 


0011:43 


67 5 


13735 3X 


;s 


0110:21 


72,6 


P. 


23271 


17 


0106:39 


81.2 


13747 A 


17 


O0CS;41 


6if 5 


NA 


23233 3 IN 


13 


a-C6:35 


GS.2 


13760 8 


IE 


01C3:5S 


V- 1 


N 


23295 


13 


Q1C--JC1 


80.0 


13772 A 


19 


0003:19 


55 9 


^JA 


23»8 3Trv 


20 


tn€l:35 


650 


13735 B 


20 


t»57:3a 


69,= 


■■J 


23321 


21 


ODc6:22 


73.7 


13793 A 


31 


0151:54 


B3 1 


NA 


3333'; BTN 


22 


0151:18 


m'.h- - 


13810 B 


23 


0051 : 1 4 


67 9 


fiA 


23345 BTN 


23 


0051-13 


77 5 


13B23A>; 


33 


0145:3- 


31 a 


N 


23359 


34 


0145.09 


31.3 


13B35B 


24 


0044:52 


66,4 


•'it\ 


23371 BTN 


25 


0016:05 


7S3 


13848 A 


35 


0130:09 


79.9 


'■i 


33384 


36 


0141 01 


90.0 


13EB0 B 


26 


003B:3O 


64,8 


•JA 


233S6 ETN 


2? 


0040:57 


76.0 


13873 A 


37 


D133:a> 


78.4 


W 


23409 


28 


0135:52 


8B.6 


13885 BQ 


26 


0032:07 


63.2 


NA 


23421 ETN 


29 


0035:48 


73-a 


13S93 A 


39 


0135:36 


76.8 


NA 


28434 ETN 


30 


0130:44 


87.5 '- - 


" 13310BX 


30 


0025:45 


61-7 



The listed data tells you the time and place OSCAR crosses the equator in an 
ascending orbit for the first time each day. To calculate successive orbits, make 
a list of the first orbit number and the neirt tVvielve orbits for that day. List the 
time of the first orhiL Each successive orbit is 1 1 5. minutes later (tvy'o hours less 
five minutes). The chart gives the longitude of the first crossing. Add 29 for 
each succeeding orbit. When OSCAR is sscendins on the other side of the 
vrorld, it will descend over you. To find the equatorial descending longitude, 
subtract 166 degrees from the ascending longitude. To find the time it passes 
the north pole, add 29 n^inutes to the time it passes the equator. You should be 
atile to hear OSCAR when it is within 45 degrees of vou. The easiest way to do 
this is to take a globe and draw a circle with a radius of 2480 miles (4000 
kilometers) from the home QTH. If it passes right overhead, you should be able 
to hear it for about 24 minutes total. OSCAR will pass an imaginary line drawn 
from San Francisco to Norfolk about 12 minutes after passing the equator. 
Add about a minute for each 200 miles that you live north of this line. II 
OSCAR passes 15 degrees from you, add another rninuta; at 30 degrees, three 
minutes; at 45 degrees, ten minutes. 



OSCAR 6: Input 
145.9ai46.00 MHz; Output 
29.45-29.55 MHz; Telemetry 
beacon at 29.45 \1Hz. 
OSCAR 7 Mode A; Input 



145.85-145,95 MHz; OliIoui 
29. 40-29.50 MHz. 
^'l o d e B : Input 
432.125-432.173 MHz; Out- 
put 145.925-145.975 MHz. 



Orbits desig:>ated "X" are closed to general use. "ED" are for educational 
use. "BTN" orbits contain news bulletins. "Q" orbits have a ten Watt erp limit, 
"L" indicates link orbit. "N" or "S" indicates that Oscar 6 is available oniy on 
northbound or southbound passes, Satellites are not available to users on "NA" 
days. 



53 



Da'Ad J. Brown VV9CG7 
RR 5, Box 39 
Nobiesvilie IN 46060 



Cheap Ears 
For OSCAR 

-- an effective satellite antenna 



Have you been thinking 
about trying to work 
through OSCAR 6 or OSCAR 
7? How about even just 
listening to it? You can 
perform a valuable service to 
amateur radio, especially 
now, if all you do is listen! 
The OSCAR beacon fre- 
quencies on the downlink 
provide AMSAT with much 
valuable data on the satellite's 
health and well-being, and, at 
the time of this writing, we 
have an ailing bird up there. 
Even though by the time you 
read this the problem may be 
cured, it has happened be- 
fore, and we aJI can help 
ourselves and AMSAT by 
listening to and forwarding 
the telemetry information to 
them. 

This brings us to the need 
for a 10 meter antenna for 
receiving the downlink activi- 
ties. The antenna described in 
this article will do a fine job 
for you for a minimum of 
cash outlay, and it has a few 
distinctive advantages over 
even the full-sized beam 



placed outdoors. First, you 
do all the aiming and rotating 
electrically and without 
rotors. Second, it has the 
advantage of being indoors in 
the attic. The second point is 
nice because there will be no 
weather wear and tear. It's 
also nice if you live in a 
neighborhood that objects to 
large outdoor antennas 
because of their appearance 
and their potential for 
causing TV!, RFI, etc. 

This antenna is only a 
group of dipoles. Many 
stations use only a simple 
dipole or folded dipole for 
OSCAR, and that is where I 
began. Once 1 tried that, I 
began to wonder what 1 could 
do to rotate it to allow for 
azimuth heading changes (a 
rotor?) and how to account 
for polarization shifts as 
OSCAR tumbles. You may 
find, as [ did, that the polari- 
zation makes the mechanical 
rotation a physical beast, if 
not impossible to control. 

About the time I discov- 
ered that, I had been reading 



an article on electronically 
steered antennas for the 
military. Between their 
thoughts for the initial idea 
and the physical limitations 
of my attic, I came up with- 
the following indoor antenna 
that beats everything I've ever 
tried outdoors, including a 3 
clement yagi. I'm sure in the 
latter case it was a matter of 
unwieldy steering and not 
lack of gain. 

The antenna is a combina- 
tion of 4 dipoles, 2 phasing 
lines, and 3 relays - nothing 
more. The main reason- it-- 
works so well is the almost 
perfect repeatability of the 
OSCAR pass for any given 
longitude equator crossing. 

Two of the dipoles lie 
horizontal, or parallel to the 
attic floor, are oriented east 
and west at the ends, and are 
/4 wavelength apart. The 
other two dipoles are a bit 
harder to explain. Half of 
each of them looks like a 
continuation of the phasing 
harness running north and 
south, respectively, on each 



end where the phasing lines 
join the first pair of dipoles. 
1 he other half of the second 
pair of dipoles extends 
straight up, or vertical to the 
phasing lines/dipole con- 
necting points, or as close to 
vertical as your roof allows. 
Mine slope inward toward the 
center feedpoint (and each 
other) at an angle of 30 
degrees off vertical. Looking 
at half of the antenna from 
the east end of my attic, so 
you arc looking west with 
your eye at floor level, gives 
you Fig. T You are looking 
at the south lialf of the array, 
and the backward "L" is one 
dipole. The box represents 
relay 2, and the circle is the 
other half of the south end 
pair of dipoles. It extends 
siraig'nt out of the page, half 
toward you, and half out of 
the back of the page away 
from you. Fig. 2 is the view 
of the north half of the array, 
viewed from the same place 
(east of the antenna, looking 
west, at floor level). The 
dotted lines in both figures 
are the vertical portion of the 
dipoles, which I-- had to slant 
toward each other because of 
my roofline. 

Fig. 3 describes how the 
relays are wired to the 
antenna to allow changes in 
pattern (or, in other words, 
steering). To describe which 
antenna goes where elec- 
trically on the relays, I use 
the fallowing terminology. 
The dipoles that lie horizon- 
tal and parallel to the floor I 
call north A and south A. The 
dipoles that have half of 
themselves vertical or perpen- 
dicular -to the floor (or 
slanted as your roof allows) 
are north Band south B. 

I haven't gone into just 
what pattern results from 
what, but I can tell you what 
the relays are doing as far as 
the antenna feed. Relay 1 lets 



r ■ 



Fig. 7. Looking into the page, you are lool?ing west. 



\0-^, 



Fig. 2. Looiiing into ttie page, you are looiiing west. 



54 



h^' 



ijiiiOlKia:' lor-rt". 



li5T .^, ^^i 








V^ EAST i£^D 






C^Pi aE MJNUTE 
L N?.^ INSTEiO 
O- -AT rjDEo 



!.U4;+ -RDM Tipr.^3 



SkO**! E\t: 



■GrZED 
Hi^wESS'r 



Fig. 3, Allow for strip and tin 
connections to relays, etc. 

you feed the north end pair- 
ISO degrees out of phase 
from the south end. Relay 2 
lets you change the feed 
phase 180 degrees on south 
B. Relay 3 lets you change 
the feed phase 1 80 degrees on 
north B. You antenna 
engineers can drop me a line 
on just what antenna patterns 
arc supposed to be occurring. I 
seem to be getting more than 
the circle of coverage would 
indicate I should, allowing 
complete passes of beacon 
coverage. The beacon is the 
best indicator, since it does 
not rely on the other station 
properly aiming his 2 meter 
antenna. 

Speaking of the circle of 
coverage you have all seen on 
maps used for OSCAR track- 
ing, mine now has a slightly 
different look. It is a grid 
with small circles at the inter- 
sections as shown in part in 
Fig. 4. The numbers represent 
the best antenna switch 
position for the satellite when 
it is over that map point. 
After a few runs, and if you 
determine where the satellite 
should be bv using a Satellabe 



on all ends of twinlead, i.e., short at outer ends of di poles, 



or equal device, you can find 
the satellite and form your 
own chart. You can immedi- 
ately see there are more than 
three numbers, representing 
more than the three individu- 
al relays. Fig. 5 .shows how 1 
have mine wired to have the 
following relay combinations: 
none, 1 only, 2 only, 3 only^ 
I and 2, 1 and 3, 2 and 3, and 
all (energized). 

Since I had automated 
control in mind from the 
beginning, I wired my relays 
and switch as in Fig. 6. By 
using a BCD output decimal 
display switch, you can 
choose any of the positions 
to 7 for any relay combina- 
tion. Once you learn what 
position you want and where 
and when, the BCD switch 
can become a tape input that 
is stepped with time during 
the pass of OSCAR. 

I did say automated, 
didn't i? Well, the tape was 
good, but the latest adventure 
seems to be the greatest of all 
ways! By hooking a 7490 
encoder to the 7445 inputs 
instead of the BCD switch or 
tape, and driving the 7490 



Switcti position 


Relays energized 





none 


1 


reiay 1 


2 


relay 2 


3 


relay 3 


4 


relays 1 and 2 


5 


relays 1 and 3 


6 


relays 2 and 3 


7 


all relays 



clock input with a variable 
square wave from a pot con- 
trolled VCO (LM 566, etc.), 
you have much what the 
military has for a steered 
antenna for radar, which 
scans the horizontal plane for 
targets! 

So far 1 have been limited 
by the switch speed of the 
relays in my system, and 
weather {no heat in attic) has 
prevented their change to a 
diode steering scheme. Now 
come spring . . . hmmm? Since 
the antenna never handles 
transmitter type power levels, 
diodes should be a cinch. If 
the ideal sampling rate can be- 
found, the antenna will be 
looking where it should for a 
long enough time to repro- 
duce enough segments of 



Fig. 4. 

good audio to sound like it is 
not switching at all. 1 believe 
this to be a rate well above 
the audio frequencies I can 
use on the relays, limited 
only by the ICs (20 MHz?), 
the diodes, and the other 
components. Someday 1 may 
be able to reduce the total 
feedline to the attic to just 
that — the coaxial feedline, 
running rf power filtered for 
the switch rate down, and all 
the switching up. 

My first idea was to tie 8 

.op amps to the age line of the 
receiver via some gates to gate 
them on with the sample 
switch. Then i' would use a 
voting system to return to the 
highest age reading on a 
sample for .1 second and go 

■'back and hold for .9 seconds 
basis (or 1,/sec sampling). If 
the age were audio derived 
and a noise blanker was used, 

~this may still be the best bet. 
At the very least, this whole 
thing offers some reaily nice 
possibilities. You could use 
"chain gang" methods of 



t 



ALL R'S lOtJK 



F 



-rr^r^,. 



^-^ 



^ 



\/ /\/ 



T^ 



Tr 



-iL_ 






Fig. 5. 



Fig. 6. 



55 



7490 connection? as blocked 
out in Fig. 7. 

The vco runs tine 7490 (B) 
at antenna switch rate. For 
the 1 out of 1 sample period, 
7490 (C) divides the antenna 
rate by 10 and only enables 
the gate ahead of 7490(A) 
during 1 of 10 periods (1/10 
of a total sample to sample 
period). Position "8" of 7490 

(A) and 7445 (A) can be used 
to do the settling and voting 
time (half enable a gate, clc.}; 
position "9" would then 
switch the antenna to that 
best antenna position decided 
on in ihe voting process. A 9 
sample period's lengili of 
time from 7490 (C) and 7445 

(B) later [for example, 7445 
(B) positions "0" and "2" 



through "9"! 
would repeat 
returning to ' 
on gate (A). 



, the process 
by 7445 (B) 

1 " and gating 
have tried to 



block diagram only one of 
several possibilities. Let your 
imagination be your guide, as 
the real intent of this article 
was the antenna itself. 

The antenna (dipoles and 



harness) is made of inexpen- 
sive TV receiver type 300 
Ohm twinlead. Since all four 
dipoles are hooked up ali the 
time (one configuration or 
another), the north pair in 
parallel represent about a 1 50 
Ohm feedpoint. The same 
holds for the south pair. By 
using a 'A wavelength harness 
from relay 1 to relay 2 
common poles and relay 1 to 
relay 3 common poles, the 
feed looking into each har- 
ness from the relay 1 end is 
about 300 Ohms. When the 
harnesses are put in parallel 
by relay 1, the feedlinc input 
point looks like about 150 
Ohms. Even though it is a 
mismatch, I attached a 75 
Ohm unbalanced (coax) to 
300 Ohm balanced balun to 
this feedpoint with no 
adverse results. This allows 
me to use the 75 Ohm RG-59 
coaxial cable down the 30 
odd feet to the basement and 
the receiver. I probably make 
up most of the balun loss, 
and then some, by running a 
pretty hot VHP Engineering 



l-;rE';\" i: '13=5 



i 


! 


1 SA;/Pi_Lh ' 
















:^L 






'A \ 








jH — 


r— 




1 

* ' 






7*A& lb 


■'J 






^j 






, 
" 




1^ 











Fig. 7. Voting system. 
ahead of the ri 



preamp 
ceiver. 

As stated before, any ideas- 
on how it works would really 



be appreciated, and any 
questions — just SASE. 
Happy OSCAR times to 
you, ■ 




Model MB II $285 
(with Balun) $315 




The NEW NYE 
"Matchmaker!" 
VIKiNG MB II 

Antenna Impedance-matching Network 
assures maximum perfectly matched 
power io your antenna! 



MB II provides: 

♦Constant SWR monitoring.* Precision tuning of final amp.* Harmonic suppression. 
* Receiver input impedance-matching.* Maximum power transfer to antenna. ♦Con- 
tinuous frequency coverage 1.6 to 30 MHz. * Precision tuning of any wire Yb 
wavelength or longer, with SWR of 1:1. 

MB II features: 

*Finest quality, made-in-USA components, *Large, precision, easy-to-read dials with 
360' readout. *Optional 3000 watt Balun for twin lead antennas. 



Available at leading dealers throughout the U.S.A. 

WM. M. NYE COMPANY, INC. 

1614 - 130th Avenue N.E., Bellevue, WA 98005 * (206) 454-4524 



W4 



56 



^lT^T] random wire antenna tuner 




sst t-2 ULTRA TUNER 

Tunes out SWR on any coax fed antenna as well as random 
wires. Works great on all bands (160-10 meters) with any 
transceiver running up to 200 watts power output. 

Increases usable bandwidth of any antenna. Tunes out SWR 
on mobile whips from inside your car. 

Uses toroid inductor and specially made capacitors for 
small size: SVi" x 214" x 2^2." Rugged, yet compact. 
Attractive bronze finished enclosure. SO-239 coax con- 
nectors are used for transmitter input and coax fed 
antennas. Convenient binding posts are provided for ran- 
dom wire and ground connections. 



only $49.95 




All band operation (160-10 meters) 
with any random length of wire. 
200 watt output power capa- 
bility— will work with virtually any 
transceiver. Ideal for portable or 
home operation. Great for apart- 
ments and hotel rooms— simply 
run a wire inside, out a window, or 
anyplace available. Toroid induct- 
or for small size: 4-1/4" X 2^3/8" 
X 3." Built-in neon tune-up indi- 
cator. SO-239 connector. Attract- 
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on 



ly $29.95 



sst t-3 

IMPEDANCE TRANSFORMER 

Matches 52 ohm coax to the lower impedance of a mobile 
whip or vertical. 12 position switch with taps spread 
between 3 and 52 ohms. Broadband from 1-30 MHz. Will 
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capability. SO-239 connectors. Toroid inductor for small 
size: 2-3/4" X 2" X 2-1/4." Attractive bronze finish. 



only !p I -/.^D 



VJv/»l\.A%l^ I t.L you are not satisfied for any reason. Please add $2 for shipping 
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P.O.BOX 1 LAWNDALE, CALIF. 
S0260-C2133 376-5337 SIO 



57 



Track OSCAR 
With Your SR-52 

-- requires the PC 100 option 



An Burke W6urx 
40JI CoJIeje Avenue 
San Diego C A 92115 



The program listed in 
Table 1 will do the 
following for you, while you 
QSO, have breakfast, mow 
the lawn, go shopping, etc.: 
(1) calculate the position of 
OSCAR 6 or 7 at the time 
intervals you select; (2) de- 
termine whether OSCAR is 
above the horizon; (3) print 
out the time (local or GMT) 
to the minute, azimuth 
(bearing), and elevation angle 
to the nearest degree only 
when OSCAR is above the 
horizon; (4) do the above for 
all the passes (northbound 



and southbound) for an en- 
tire day (longer, if desired); 
and, finally, (5) do this 
wherever you are in the 
world. 

Item 5 is especially impor- 
tant for those hams operating 
near the equator or in the 
Southern Hemisphere. The 
usual formulas give erroneous 
azimuth pointing angles when 
OSCAR is south of the 
equator. Formula 3 (see 
below) corrects for this con- 
dition. Additional features 
are that yoLir QTH is stored 
in registers 98 and 99 (un- 
affected by "clear mem- 
ories"), and all OSCAR orbit 
data is stored in the upper 
data registers (15-19), so the 
calculator can be used for 



other problems without 
disturbing the OSCAR data. 
Let's examine item 5 in 
more detail. Fig. 1 shows the 
actual OSCAR track (solid 
line) for the example given 
later where OSCAR crosses 
the equator northbound at 
78.1° West, and the apparent 
track in the Southern Hemi- 
sphere (dotted line) of the- 
track for the preceding orbit 
which results in the 78.1° 
crossing. The usual formulas 
(which arc good only in the 
Northern Hemisphere) will 
make OSCAR apparently 
change course as soon as it " 
crosses the equator. Thus, 
instead of continuing in a 
southwesterly direction after 
crossing the equator -at- ■ 




Fig. h OSCA R paths, actual and apparent, on the Earth. 



243.7° W., OSCAR apparent- 
ly abruptly turns south- 
easterly, as shown by the 
dotted line, and ultimately 
crosses the equator in a 
northeasterly direction at 
78.1 "■ W., and then abruptly 
turns and proceeds in the 
correct northwesterly direc- 
tion. Of course, OSCAR 
doesn't really do these acro- 
batics, but formulas 1 and 2, 
as usually given,' which cal- 
culate the latitude and longi- 
tude of OSCAR at the select- 
ed time intervals, give these 
apparent positions. And, 
since these positions are used 
in conjunction with our own 
positions on Earth (latitude 
and longitude of our QTH} to 
calculate the direction to 
point our antenna at OSCAR, 
we vvii! be wrong! 

Well, if this is really so, 
why haven't we hams in the 
United States noticed this 
before? Why do the formulas 
seem to work ol<ay for us? 
The answer is that we are so 
far from the equator, and our 
antennas have broad enough 
beamwidths .. (approximately 
40° wide atthe^'3 dBdown" 
points for a so-called 
13 dB beam), that the appar- 
ent "dogleg" in the path Is 
entirely contained within our 
beam coverage and goes un- 
noticed, I have shown a 40° 
beam pointed from Miami 
toward the 78,1° W. crossing 
in Fig. 1. Notice how it 
encompasses both the true 
and apparent paths of 
OSCAR within the "OSCAR 
horiron " of Miami, shown as 
the dotted arc centered on 
Miami. And, of course, the 
effect is diminished as we are 
even further north, because 
OSCAR is in range below the 
equator for a shorter distance 
(or not at all), and the an- 
tenna beam covers a large 
area below the equator. 

Now let's take a ham in 
Quito, Equador, whose QTH 
is at 0.2° S. latitude and 
78.5° W, longitude. He is 
really in trouble if he uses 
formulas 1 and 2. His 
calculator will tell him to 
point his antenna in a 
southwesterly direction to 



58 



pick up the approaching 
OSCAR, instead of the cor- 
rect southeasterly direction. 
Although his antenna may be 
40° wide, it is not wide 
enough to include the direc- 
tion of OSCAR, as shown by 
Fig. 1. 

In even worse shape would 
be a ham in New Zealand, for 
example. The apparent path 
of OSCAR is south of him, 
heading east, when in reality 
it is clear around the world 
below South Africa. 

The part of equation 2 
that causes this trouble is the 
first portion in the brackets: 

I hVV cos{cos — p — /cos L5H 

When OSCAR is in the 
Northern Hemisphere, but 
approaching the equator, it is 
a trifle less than /; P, since it 
is the time since OSCAR 
crossed the equator going 
north, and P is the time of 
the full orbit. Thus 360t/P 
will be less than 180 (let's say 
176.9, for example). The 
cosine of 176.9° is -.998.54, 
Ls, the latitude of OSCAR 
from equation 1, is about 3"; 
its cosine is .99853. The re- 
sult is the inverse cosine of 
-.99991 or 179.2°. Now, let 
the OSCAR go an equal dis- 
tance past the equator so that 
360t/P is 183.r. The cal- 
culator computes the cosine 
as -.99854 (the same as for 
176.9); the latitude is now 
about 3 S. or -3°, whose 
cosine is .99863 (the same as 
for 3"). The result is that the 
calculator give you the same 
inverse cosine of -.99991 = 
179.2° as before. After all, 
how can the calculator know 
that you want an answer 
greater than 180°? Thus, the 
OSCAR seems to be back- 
tracking in an easterly direc- 
tion as it heads south, and 
gives the apparent track as 
shown in Fig. 1 . 

The answer to this prob- 
lem is simple: If the latitude 
of OSCAR is positive (north 
of equator), use the equation 
as is; if the latitude is neg- 
ative, subtract the angle ob- 
tained from the bracket from 
360° (e,g., 360 - 179,2 = 
180.8), and use that value of 
longitude in the subsequent 



calculations. (In the program 
listed in Table 1, 1 have done 
the equivalent by testing the 
sign of the sine of L5 to save 
program steps.) 

For those hams with an 
interest in how and why 
things work (most of us, 1 
think), here are the formulas 
used and a brief explanation 
of their place in the program. 
1 and 2 are adapted from 
reference 1 ; the other ex- 
pressions are from reference 
2. 



1. L5 ^ INV sin {sin a sin 



350t 



2. :\3- [INV cos (cos -p~- /cosUl] 

3. [fs'trr Ls is positive, 
As is as c'iven by 2. 

]f sin Lg is riot positive, 
?.5-360- [1 ^ >.x -^^ 1115} 

5. c ^ INV cosisin Ls sin Lq ^- 

cos Ls cos Lq co5 v) 
Q. 3^ INV cos I (sin L^^ 

sin Lq cos cl/{cos Lq sin cj] 
7. If sin V is posillue, 

B = 360 - ;^ 

If sin V is no^ posi'Jve, 

B. EL= INV tan |(co5C ■ 
-=— )/sinc] 



where (all degrees are in 
decimal form, e.g., 24.1 ): 



Ls is the latitude of 
OSCAR in degrees — positive 
if north of equator, negative 
if south; 

a is the inclination of 
OSCAR'S orbit in degrees 
counterclockwise from east; 

t is the time in decimal 
hours from Tx; 

Tx is the time of a north- 
bound equatorial crossing by 
OSCAR, in hours and min- 
utes (GMT or local); 

P is the period of the orbit 
in decinnal hours; 

As is the longitude of 
OSCAR in degrees west from 
Greenwich, England; 

Xx is the longitude of the 
northbound equatorial 
crossing (at Tx) in degrees 
west; 

Aq is the longitude of the 
QTH in degiees west; 

Lq is the latitude of the 
QTH in degrees — positive if 
north of the equator, negative 
if south; 

B is the azimuth (bearing) 
to OSCAR from the QTH in 
degrees clockwise from nbrth; 

EL is the elevation angle 



to OSCAR from the QTH in 
degrees, from the horizontal 
upwai'ds; 

R/(R+h) is the ratio of the 
Earth's radius to the sum of 
Earth radius and orbit height. 
Program steps 000 to 009 
initialize the program, fix the 
decimal point to four places 
(necessary for accurate time 
displays later), print the en- 
tered time, Tx, convert Tx 
into decimal hours, store it in 
register 11, and bait, ready 
for the next entry. When Xx 
is entered on the keyboard 
and RUN is pressed, steps 
010 to 017 store Xx in reg- 
ister 14, print it, and put a 
in register 13. Steps 018 to 
1 38 solve equation 1 and 
store sin L5 in register 63. 
Steps 039 to 080 solve ex- 
pressions 2, 3, and 4. Steps 
081 to 157 solve 6 and S. 
Steps 158 and 159 test the 
elevation angle and, if neg- 
ative, skip to step 214, after 
which At (your selected 
orbital time interval) is added 
■ to register 1 3, and the pro- 
gram repeats, beginning with 



0-377. 0700 


PRT 


14. 


PRT 


289. ■ 


., PRT 


IS. ;38U0 


PRT 


22. 42 


PRT 


1 . 


PRT 


78. iOOU 


PRT 


301. 


PRT 


17. 50 


PRT 


IS. 't6 


PRT 


9. 


PRT 


fc.S. 


PRT 


QQ_ 


PRT 


3. 42 


PRT 


j^'. 


PRT 


H. 


HP 1 


31. 


PpT '■ - 


1?. 54 


PRT 


IS, 5C 


PRT 


^_'. 


PRT 


45. 


PRT 


7 -.., 


PRT 


3. 46 


PR~ 


4^ 


PRT 


1 6. 


PRT 


43. 


PR"^ 


17. 58 


PRT 


IS. 54 


PRT 


25. 


PRT 


"' ~" 


PRT 


'-'-■ ■"* . 


PRT 


2, 50 


FRT 


2. 


PRT 


■ 6. 


PRT 


J5. 


PRT ' ~ 


15. 3S 


PRT 


Ifi, 1^1 :-: 


PRT 


■-t i . 


PRT 


126. 


PRT 


' ■-! 


PRT 


'~z. 54 


PRT 


14. 


PRT 


7_ 


PRT 


: 4y 


PRT 


19.42 


PRT 


20. :;:4 


PRT 




PRT 


99. 


PRT 


i &2. 


pRT 


S. 5S 


PRT 


■-; ■"■ 


PRT 


cr 


PRT 


1 6 , 


PRT 


15^46 


PRT 


20. 3o 


PRT 


iu. 


PRT 


"~ 43. 


PRT 


162, 


PRT 


to. 34 


PRT 


3,-. 


PRT 


24. 


PRT 


4. 


PRT 


19. 50 


PRT 


2ri. 42 


PRT 


5. 


PRT 


1- ■ 

Q, 


PRT 


iK4. 


PRT 


10. 3S 


PRT 


19, 


PRT 


tiZ. 


PRT 


250, 


PRT 


1 3. 54 


PRT 


20. 46 


PRT 


2 - . 


PRT 


355. 


PRT 


3 - l: . 


PRT 


10. 4 2 


PRT 


3, 


PR" 


_ 4 w 


PRT 


210, 


PRT 


2 1 . :30 


PRT 


2U, 50 


PRT 


- c 


PRT 


134, 


PR' 


:-■-::'. 


PRT 


12, 46 


PRT 


1 V 


PR^ 


20. 


PRT 


2 5 6 , 


PRT 


21, 34 


PR' 


20. 54 


PRT 


30, 


PRT 


217. 


PRT 


::: ^ 4 . 


PRT 


!";, =:n 


PRT 


30. 


PRT 


■^■ 


PRT 


233. 


PRT 


21. 3 y 


PRT 


22. "■'"' 


PRT 


■ 2. 


PRT 


2 ('---. 


PRT 


2 2 C' . 


PRT 




PRT 


40. 


PRT 


:-;, 


PRT 


335, 


PRT 


2 I . "2 


PRT 


22. 2^ 


PRT 


3. 


PRT 


314, 


PRT 


242. 


PRT 


12, 34 


PRT 


22. 


PRT 


11. 


PRT 


312. 


PRT 


21. 46 


PRT 


22. 2S 


PRT 


4. 


PRT 


■-[ ■-! "^ 


PRT 


27:-;. 


PRT 


12,3 S 


PRT 


~~~e'. 


PRT 



Fig. 2. Printout of 36 hours of OSCAR 7. 



59 



LBL 
A 

fix 
4 

Ert 
.MS 
STO 
1 
1 

HLT 
STO 
1 

4 
grt 

STO 
1 



I 



:CL 
1 
3 

ECL 

1 

? 

STO 

sin 
I 

RCL 

I 

sin 

STO 



t pos 
tan 





LBL 
tan 
( 
ECL 

9 
COS 

RCL 

6 

3 



000 46 

001 11 

002 57 

003 04 

004 98 

005 37 

006 42 

007 01 
OOS 01 

009 SI 

010 42 
Oil 



01 ; 
oi; 



01 
04 
98 



014 00 

015 42 
01 



1 D 

017 
Olt: 
019 

020 03 

021 65 
022 
023 
024 

025 95 

026 42 
02? 
023 
029 

030 65 

031 43 

032 01 

033 06 

034 32 
035 
036 
037 
03 S 
039 
0401 
041 
042 
043 
044 

045 46 

046 34 

047 53 
04b' 43 

049 06 

050 09 

051 33 

052 55 

053 43 

054 06 

055 03 



43 
01 



43 
01 
05 



06 
09 
32 



sFi 
42 
G;- 
03 
SO 
34 
03 
06 
00 
75 



INV 
Sin 
cos 
STO 

4 
) 

INV 
COS 

+ 

RCL 

1 

3 

X 

+ 

ECL 
1 
4 

RCL 



STO 
1 

2 
cos 

ECL 



cos 

X 

ECL 
4 

ECL 



sin 

X 

ECL 



STO 



INV 
COS 

sin 
STO 

6 



056 
05? 
055 
059 
060 
061 
062 
063 
064 
065 
06b 

lib? 

068 
069 
070 
071 
072 
073 
074 
075 
076 
077 
073 
079 
030 
031 
0S2 
083 
084 
085 
036 
OS? 
OSS 
039 
090 
091 
092 
093 
094 
095 
096 
09? 
098 
099 



42 
06 
04 
54 



85 
43 
01 
03 
65 
01 
05 
85 
43 
01 
04 
75 
43 
09 
09 
95 
42 
01 
02 

65 
43 
09 
03 

65 
43 
06 
04 
85 
43 
09 
03 



RCL 



COB 

~^/x 
! 

ECL 

3 
RCL 



sin 

X 

RCL 



iCL 



INV 
tan 
STO 



100 43 o 

101 06 6 

102 03 INV 

103 95 if pos 

104 42 COS 

105 06 RCL 

106 07 1 

107 22 1 
inft 3": + 

109 32 RCL 

110 4 2 1 
HI 06 3 

Table 1. OSCAR SR-52/PC 100A 



112 
113 
114 

ns 

116 
117 
lis 
119 
120 
121 
122 
123 
124 
125 
126 
127 
128 
129 
130 
131 
132 
133 
134 
135 
136 
13? 
1 38 
139 
140 
141 
142 
143 
144 
145 
146 
147 
14S 
149 
150 
151 
152 
153 
154 
155 
156 
15? 
15S 
159 
160 
161 
162 
163 
164 
165 
166 
167 



65 
43 
09 
08 
33 
95 
20 
65 

43 
06 
03 
75 
43 
09 
08 

65 
43 
06 
07 
95 



42 
06 
05 
43 
06 
07 

43 
01 
08 
95 
55 
43 
06 
08 
95 
22 
34 
42 
06 
06 

SO 

33 

43 

01 

01 
c-r 

43 
01 
03 



program. 



INV 

D.MS 

fix 

2 

2 

4 

if pos 

log 

+ 
2 
4 

LBL 
log 

icL 

1 

2 

sin 

INV 

If pos 

sin 





LBL 
sin 
ECL 



168 95 

169 22 

170 37 

171 57 



JTO 



172 
173 
174 



2Ufc. 
20? 
20S 
209 
210 



21 ; 
2U 



02 
75 
02 



175 04 

176 95 

177 80 

178 28 
1?9 85 
180 02 

131 04 

132 95 

153 46 

154 28 
185 9S 
136 43 
IS? 01 

188 02 

189 32 

190 22 

191 80 

192 32 

193 03 

194 06 

195 00 

196 75 

197 46 

198 32 

199 43 

200 06 

201 05 

202 95 

203 5? 

204 00 

205 98 



43 
06 
06 
98 
5? 



211 04 

212 46 

213 33 

214 43 

215 01- 

216 07 



44 
01 



219 03 

220 41 

221 OD 

222 Ot 

223 08 



step 01 8. 

However, if the elevation 
angle tests as not negative, 
steps 1 61 to 21 ) add t to J^, 
convert the result to hours 
and minutes, and print. Then 
they apply expression 7, print 
azimuth and elevation to the 
nearest degree, refix the 
decimal point to 4 places, and 
go to step 214, where the 
cycSc begins again. Thus, a 
printout is made only when 
OSCAR is not below the 
horizon. Labels sin, cos, tan, 
and log are used internally to 
save program steps. 

OK, so much for the sales 
pitch and the explanations — 
how do we go about using the 



program? Simple! Here is a 
step-by-step procedure: 

FIRST — Key in the pro- 
gram listed in Table 1 (don't 
forget to either reset or GTO 
000 before pressing the LRN 
key). Now, press LRN to put 
the calculator back into the 
calculate mode. Record the 
program on a magnetic card 
for future use. If you already 
have the program on a card, 
enter it in the usual manner, 

SECOND - Key in the 
west longitude of your QTH 
(Aq) In decimal degrees and 
STO 99; key in the latitude 
Lq in decimal degrees (if 
south of the equator, key +!- 
for the minus sign) and STO 



98. 

THIRD - Key in the fol- 
lowing OSCAR orbit data, 
and store as shown: 

1.916 STO 19 (P) 
0.813 STO 18 [R/(R+h)l 

101.7 STO 16 (a) 
187.9 STO 15 (360/ P) 

(These values are averaged for 
OSCARS 6 and 7 and give 
good results for at least 36 
hours of orbit. You can, of 
course, put more accurate 
values in if you wish.) 

FOURTH - Key in your 
desired orbital time intervals 
(^t) in decimal hours; e.g., if 
you want 4 minute -^t, key 4 
-^ 60 =, and store the result in 



register 17 by STO 17. (This 
will store 0.0666656667 in 
reg. 17 for this example.) 

FIFTH - Set the R-D 
switch to D (degrees). 

This completes setting up 
the calculator with its per- 
manent data base. Note that, 
if you have already used the 
program, then replaced the 
program with another to 
work on some other proi3lem 
but have not turned off the 
calculator or otherwise dis- 
turbed registers 15 through 
19, 98 and 99, the second 
through fourth steps can be 
omitted. 

Now let's take an actual 
example (which can be used 
by you as a "check" prob- 
lem), using my QTH (Lq 
32.75, Xg 117 are stored in 
registers 98 and 99), and 
OSCAR 7, beginning on the 
evening of July 3, 1977, 
Pacific Daylight Savings 
Time. Page 16 of the July, 
1977, issue of 73 Magazine 
lists orbit 12044, A mode, 
July 4, 0138:05 GMT, 78.1°. 
This is July 3at 1838:05, my 
time. When I enter Tx, 1 can 
use either GMJ (1.38) or 
POST (18.38), as I choose. 
The resulting times will then 
be in the same time zone. I 
will choose POST and enter 
to the nearest minute in H.M 
(Hours. Minutes) as follows; 

STEP 1 - (opti-onal) Key 
703.77.07 PRT to print my 
Pacific date and indicate 
OSCAR 7 (07). 

STEP 2 - Key 18.38 (Tx 
in H.M). 

STEP 3 - Press A (the 
calcuflator will stop, showing 
18.6333, which is Tx in 
decimal hours, and wiii prir^t 
18.3800 PRT). 

STEP 4 - Key 78.1 (Ax). 

STEP 5 -Press RUN. 

Now you can relax and do 
other things, as you wish. The 
calculator-printer has taken 
over. It will immediately 
print 78.1000 PRT, thus 
giving you Tx and Xx for 
reference. It will then print 
out the time (in H.M), 
azimuth, and elevation angles 
in degrees every 4 minutes of 
orbit time that OSCAR 7 is 
within the QTH's horizon, 
throughout the rest of the 



60 



night of July 3 and through- 
out July 4, It lakes the cal- 
culator about 13 seconds for 
each At, thus the first print- 
out will be about 40 seconds 
after you pressed RUN, be- 
cause the satellite is not 
above the horizon until 
18.46. At that time, the 
azimuth is 99°, and the ele- 
vation is 8°. It will take the 
calcuSator approximately 70 
minutes to finish 24 hours of 
orbit time, and thus about IK: 
hours to finish the |uly 4 
evening passes. Fig, 2 is an 
actual PC 1 OOA tape for this 
example. 

OK, you say, that's fine 
for a west coast ham, because 
the orbits listed in 13 are 
usually the first ones that are 
within range of the west 
coast. But how about some- 
one on the east coast? It's 
still simple: Take that orbit 
for July 4 GMT, and subtract 
115 minutes and 28,75° 
several times from the listed 
values in 73 until you get the 
Tx and Xx of the first orbit 
that vvill be in your range. 1 



have found that the first 
northbound orbit must be 
about 65° or less east of my 
QTH to be within range; this 
should be suitable within the 
48 states and Hawaii. 

Or, for the really lazy (or 
busy?), just start with the 
preceding day's first orbit, as 
listed in 73, and let the cal- 
culator crank out about 36 
hours of orbital data. This 
suggestion is probably the 
easiest for hams in the 
equatorial and sub-equatorial 
regions to use, because their 
usable passes will be either 
northbound passes, starting 
from below the equator, or 
southbound passes. 

Well, so far so good, for 
the fat cats with the printers; 
now, how about those of you 
v/ith the bare bones SR-52? 
Here's how: First, put in the 
progi"am and data registers, 
just as indicated earlier, but 
with 3 simple changes. 
Change program steps 185, 
205 and 209 from prt (98) to 
HLT (81). The calculator is 
used in the same way, except 



that paper and pencil are used 
instead of the automatic 
printer. 

After 'I j( and Xj^ are en- 
tered as above, the calculator 
will halt and display the first 
time the satellite is in your 
range. After writing it down, 
press RUN, and the calculator 
will halt with the azimuth 
displayed. Write it, press 
RUN, and the calculator will 
halt with elevation displayed. 
Write it, press RUN, and a 
new time will be displayed 
when the calculator halts, 
etc., etc. However, remember 
that each calculation cycle 
takes about 13 seconds, so 
that, if the satellite takes 12 
minutes to come into range, 
as in the example above, it 
will be about 40 seconds 
before the calculator halts 
with the first time display, 
and, after the OSCAR goes 
beyond your horizon, it will 
be about 5 minutes before 
the calculator halts with the 
next northbound pass in 
range displayed. It wilf be 
much longer than that, after 



the last northbound pass, 
unril the first southbound 
pass comes within range. You 
may find it more convenient 
to press HLT, if no display 
has appeared in 20 seconds 
after a series of displays. 
Then, add (use the calculator 
for this; it won't hurt the 
program) 115 minutes to the 
previous T^ and 28.75° to 
the previous Xx, enter these 
new values for the T^ and Xx 
in the program, and you thus 
bypass the time to circle 
the world. A convenient way 
to do this is to key in the 
previous Tx (e.g., 18.38), 
press D.MS, +, RCL 19, = 
INV D.MS, and then press A. 
At the halt, key in the pre- 
vious Xx (e.g., 78.1), press +, 
28.75, -, and then press 
RUN, 

Well, there it is. Have fun 
with the program and good 
hunting on OSCAR. ■ 

References 

Iw. Danielson and S. GEick, QST , 
Oct., 1969, pg, 54, 
2hP-65 program, by Dr. Earl F. 
Skelton WA3THD,Aug., 1975. 




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COMMCmiCATIONS SPEQAUSTS 

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61 



Try A TR 
For OSCAR 8 

-- turnstile over reflector system 



David J. Brown W9CGI 
RR 5, Box 39 
Noblesvilk IN 46060 



T-R, in this case, is 
/"urnstile over /deflector 
antenna, and it could def- 
initely aid your OSCAR per- 
formance. Built for three 
band capability, it will do 
weil for you on the present 
OSCAR satellites, not to 
mention the upcoming 
AM SAT high orbit type 
machine. If you think using 



mechanical tracking rotors 
for the present OSCARs is 
tough, the next one is going 
to be impossible for you. 
True, it moves more slowiy, 
relative to a position on 
Earth, but I'm sure we will 
hear the same, "Where the 
heck is it?" comments v/e had 
about OSCARs 6 and 7. 

Referring to Fig. 1, 1 have 
only shown the two-band 
2m/1 Om version, because that 
is all I have had a chance to 
check out. There is no reason 
at all why iwo ten-foot masts 



— CUSHCRAFT 
^- 2M DRIVEiN 

ELEMENTS 




could not be used in place of 
the ten- and five-foot versions 
shown for the vertical mast. 
An alternative is to build it as 
shown, and, due to the very 
small size of the Vim version, 
it could even be bracketed to 
the top at a later date. That is 
my reason for drawing the 
unused extra j^ wavelength of 
mast poking out of the top 
on 2m. 

Construction is entirely 
with commercially available 
antenna parts (especialFy 
from Hy-Gain 64Bs). The 
crossed dipoles on the 10m 
T-R can be 10m beam driven 
elements. Two of these-are- 
used on mine, less the beta 
matches, and with the ele- 
ments stretched out to 10m 
dimensions. I did this by 
using some CB antenna alu- 
minum tubing. These tubes 



L0#e3 Mas 

TV MAJT 
ir LONG 




were the same o.d. as the 
tube/reducers on the original 
64B and fit nicely into the 
64B dipole insulators. The 
old 64B element o.d. is not 
quite the same as the i.d. of 
the new CB tubing, but there 
are ways around this. You 
can wrap the smaller element 
with aluminum foil and then 
clamp it into the larger ele- 
ment with hose clamps, or go 
the more complex route I 
went. I added plugs about 2 
inches long, that were bored 
out and tapped on one end to 
3/8-24. This exactly matches 
the threaded stud on a full- 
size stainless steel CB whip, i 
obtained several of these 
whips, that had been 
damaged in one way or 
another, but still had good 
studs and about 40 inches 
plus of undamaged whip. If 
you figure out the average 
height of a car versus a 
bumper-mounted CB whip, 
believe me, there are several 
whips in this condition 
around. They are worthless to 
use on CB, so you can buy 
them even cheaper than the 
replacement full-size whips. 
My CB aluminum tubing 
came out at 56 inches, so the 
whips were cut off at 39 
inches and screwed into the 
plugs. The plugs are held in 
the tubing by 14-20 hardware 
through the tubliig and plug. 

For the reflectors, I used 
the CB parts that would nor- 
mally be the ground plane 
elements. The largest parts 
just fit the same insulators, 
and' then are grounded to the 




Fig. 7. Vertical mast is 10' x 5' heavy-waf/ TV mast (bolt 
through Joint). Cut off lower flare to fit into or onto CB base 
used. 





!J niwER - 



^ -ye OF 'c*tn r.R 



Fig. 2. /Mounting. 



62 





General 


@fo in Fig. 1. 


2m driven 


234/f„ 


1 9.24" 
48.9 gm 


2m reftected 


234/fo + 5% 


20.2" 
51.32 cm 


10m driven 


234/fo 


95.2" 
241 .8 cm 


10m reflected 


234/fo + 5% 


99.94" 
253.86 cm 


Table 1. Mast CTR to tip of element. 



FEt[! I = 2oon 



boom by a 1-inch wide straps good antenna and have it die 

from feed clamp to boom to a month or two later, so 

feed clamp. If you order please forgive m& for belabor- 

parts, just use the director ing the tape and spray rou- 

clamps instead, and the ele- tines, 

ment will be already Fig. 2 covers mounting 

grounded. possibilities. The array size. 

The 2m T-R is not much weight, and low wind load 
different. You can even use a make it a reasonable candi- 
plate and CB whips (or the date for chimney mounts, 
parts cut off above) to make Just remember this is a last 
the reflector elements. You resort spot for antennas. It is 
only need pieces about 20 the most corrosive, thermally 
inches long. Simple brackets changing, lousy spot avail- 
will mount them to the able, but if it's all you have, 
vertical mast. it's all you have. I used the 

The driveri elements are side bracket method, with the 

made to order, used as is, lower ground planes about 20 

parts from the A147 type feet off the real ground. It is 

CushCraft antennas. They are on a tower that also has two 

just the driven elements from stacked halos for a backup on 

those antennas. When ! lost 6m and the Hy-Gain 66B 6m 

the EME array awhile back, I yagi up on top. None of the 

saved the parts off the broken 6m goodies seems to cause 

3 yagis. They are 50 Ohm, shadows or create any loading 

coaxia!-fed dipoies with effect problems. It all looked 

gamma matches, so it can't be the same looking into the 

much simpler. Even their feedpoints up and mounted 

mounting method is obvious as it did on the ground. The 

from their construction. 2m swr was very good at 

All that leaves are the 1.15:1, and it is not worth 

matching harnesses. A letter messing with to improve. The 

to Hy-Gain produced the 10m must be getting a little 

figure of 200 Ohms for a pattern distortion, no doubt 

feedpoint impedance using from the tower; but it had a 

the dipole alone — no beta 1.1 ;1 on the ground and a 

match. The harness of Fig. 3 1.25 ;1 now. It works fine, 

shows the material and and I'm not going to push it 

cutting instructions. Use good to get a little more here and 

lugs on the bolted connec- there. 

tions, tape well, and use a This whole story seems 

good quality, clear spray terribly short, but then there 

liberally. Since the clear sets just was not much to the 

up so rapidly, I have found 4 constmction, either. One 

or 5 light coats work better weekend of an hour here and 

and crack less. an hour there, and it was 

The 2m harness is even both done and up. The anten- 

easier, since it uses all coaxial na design is not new, but I 

connectors. iVleasure and thought you might like to 

solder carefully, and check all share some of my construc- 

the harnesses piece by piece tion methods, 

for braid to center shorts, as Here's one final note of 

each piece is completed. Then help: When you get it all 

screw it all together and to together, try the following: 

the antennas, and tape and As the beast gets larger (as 

spray well. Nothing is more you add the 10m hardware), 

disgusting than to buiid a it pays to have a pipe stuck in 




O'.E d:^0_£ 



"ST 



t 



© 



[:0&J ^ '.y:' Wn^-52rt/U [lOel 



ItidJ 






LINE I ' zc-^/ziM ■ loen 

LINE 3- rC^/ZIN -106 il 
LINE 2"JC^/ZIN-eiJl 

^'ORl LINE I a PORT LINL 2 IN ll : 



SM PHASE 6 MATCH 50n DOWNrEfiD 
HG-e, RG- 2I3.be LDEN 9311 
>.^4 AT 66 VEL FACTOR = 13 l.n 

OR ^BESTIUSE KLN^ 1 PORT COUPLER 



Fig. 3. Feed and phase. 

the ground that you can expanded part), you wind up 

U-bott it to and work on it with a quicky test setup for 

upright. I have a 4-foot pipe checking out small antennas 

stuck 3 feet in the ground in at 21 feet off the ground, 

a post hole and filled around Even some of the .small and 

with concrete. Level the lightweight 6m beams aren't 

concrete off with the ground "too big to swing up. For 

in sympathy for your lawn larger antennas, two water 

mower. Don't place it where pipes in the post hole, with 

you can break a leg on it, and the mast pivoted between 

you have a utility mast and them (tilt-over tower style), 

antenna holder. If you saw aiso work well, 

the expanded end off of a TV Keep me posted on how it 

mast (as you will do in all works out for you, prefer- 

making the vertical mast in ably when 1 hear you having 

this article), and make the fun on OSCAR. I mounted 

cut-off piece about 8 inches mine in a direction southeast 

long, you will end up with a from the tower, due to the 

dandy test setup. Keep two tower sides' orientation. The 

10-fool TV masts around (up way the legs are on my tower 

in garage rafters, etc.), and, if left me the general directions 

you fit them together to of 0, 120, and 240 degrees, so 

make a 20-foot mast, add the I chose the 120 degree direc- 

sawed off piece to the un- tion. 1 favor the early evening 

expanded end of the 20Toot passes east of me, since I can 

pair, use the whole business be home and make more of 

upside down (ejq^anded ends them. It aiso does just fine on 

up), and choose your 4 feet passes west of me, too, so 

of water pipe in the ground have no fear of it being deaf 

with an ID larger than the TV off the tower side. See you 

mast (but smaller than the on OSCAR. ■ 



63 



Thomas A. PrevAU V/9IJ 
221 2 S. V'/ebsrer 
Kokomo JW4690J 



Track OSCAR 
In Real Time 



-- with your HP-67 calculator 



Program Doscriplion 



Umt liiKfruc'lioiivS 





HP t7/?7 


C/^LCUl.-=.TOR 




PRjgrMFmie 


OSCAR TRACK 






I1«{n« 


T.A. i'tewit-i W9IJ 




o^e 5/22/77 


AtJGiew 


221J s. Webster 






C[y 


Kot^omo 


State ih- 


ZpCMa 4 6901 



Program DcscilplPon. EqiJBHons, Va.lablEs. ele„ Adapted from equations given in 

Computerized Satellite Trackincf, 73 '-iagaaJne , February, L977, 
page 12, by WBj3JHS. 



Store these constants in the indicated registors 

■1 Longitudi? incren:ent [28.7363)* 

5 3SC 

6 1/60 

8 Xncliniition t:o ei^uatir (lOi.77) 

g Period fU';,545: 

12 -1 

13 36D 

15 Height (3101 

16 Latitude of your station 

17 Longitutle of vour station 
la 3S39 

15 69.05 

Values in pare^itheses axe for OSCAR VII 



OpeT..ting um.i5*n? w»rn'n:s Program has been checked for scatior. locations 
in North latitude and :-faBe lornj-.tudo, should vors for East 
longitude if longitude is eo^plprented. 



DO NOT UBC IHB fiPME 



64 



OSC?iR TRACK - 70522 



KEXT 
QR3IT 




STEP 


tHSTDUCTlOHS 


IHCUT 
□ ATA .'U Hit; 


Fi.e¥S - - : 


auTPur 

OArwunnS 




1. 


Load PLograwL and Data 




1 II ; 






-. ^ .- 




i W 1 

1 E.ji 1 
1 II 


_... 




2. 


Enter Kifference Orjbit Dafea 


lirbiL i 

GMT ^H, MS 














Long . 












3. 


Tlj !jk:.;; Ahead N Orbits (Emtediateiy 


"bjl 


k/E , 

1 II 1 


Orbit ! 






>-^lloh-inq 2). ■ . , . - 
























^*^ 




3a, 


To i.Oi&k Ahi^iad <^m Ocbi^ 




' 0.1 1 1' 
II \ 

- II 1 
II 

1 II 

1 II 1 

1 II 1 

■ft.]' 1 
1 11 1 
1 'I \ . 

1 J 1 

1 il 1 

1 II 1 

I II 1 

11 1 


Or?*it i 
Vine 


















4.' 






To TracX AZ-EL in Real Tiin^ 


Duriny A Piiss, First Perforrn 






- - 


1, 2 and 3 (If Needed) . Wait 








lentil Rniii Time Reaches 




KotH ~' 






Timfi ^nh?iv?n iTi Display 










































Hot* 1 - biaplay IXirin^ TracJE ."tode Co 


nsists 


- - 


3f ri.^ijsec Time ir. Hij-.yres, 




?(jllowed 3y A Zero and 








y.Z-YX Bearijigs. AS P'.r.cle 






w 






n^pf^ars IiHTieciatel,v ^o Left 




Of Lwrimal Point And t^ 






Artcrle Is Irunediacely to 




j ' 




Right Of Deciinal ?oijit, t/hich 




1 

1 11 1 
1 II 1 
1 II 1 
1 II 1 






Serves Onlj^ As A Seoarator. 








EL la Zero If Satellite !•&. 






B&Xnw Horizon, 























In the February (1977) 73, 
Henson* presented a 
beautifiilly-documented mini- 
computer program for track- 
ing OSCAR. The program 
described here calculates and 
displays the same information 
(except range), and, in addi- 
tion, runs in real time during 
a satellite pass. Written in 
RPN for a Hewlett-Packard 
HP-67 pocket calculator. It 
will run on an HP-97 as well. 
I'm sure that an equivalent 
program could be written for 
the Tl SR-52, although i have 
not done so. 

After loading the program 
and data constants, begin by 
entering reference orbit data. 
Then step ahead one or more 
orbits to the one of interest. 
The calculator will pause to 
display the orbit number and 
the longitude of the' equa- 
torial crossing, and m\\ halt 
with the display containing 



*Henson WBCJHS, "Computer- 
ized Satellite Tracking," 73, Feb- 
ruarv, 1977, p. 72. 



the predicted time of the 
equatorial crossing (with all 
data needed for a real-time 
track of the satellite on the 
selected orbit stored in the 
proper registers). 

When real time (clock 
time) reaches the time shown 
in the calculator display, 
press the "TRACK" button 
to commence a real-time 
track. Thereaiter, the pro- 
gram will run continuously, 
calculating beam-aiming data 
once each minute, and paus- 
ing every few seconds to 
display the current results. 

Several data display for- 
mats have been programmed 
and evaluated. Although 
many tracking parameters can 
be calculated, the ones finally 
selected for display are the 
eiapsed time, the beam head- 
ing, and the elevation angles. 
To keep the waiting time 
between successive displays 
to no more than a few 
seconds, these three data 
items are merged into a single 
line, which is displayed three 
times as frequently as each 



Minutes past equator 

^zimuth angle, degrees 

Elevation angle, degrees 



2 2 13 6 .47 



'^Decimal point 
serves as a 
separator 



Fig. 1. Typical merged display. 



would be if they were dis- 
played in sequence. 

Fig. 1 shows a typical 
merged display. The elapsed 
time, in minutes, appears to 
the left of the first zero. The 
azimuth heading appears to 
the left of the decimal point, 
and the elevation angle is 
shown to the right of the 
decimal point. Both angles 
are in whole degrees, and the 
decimal point serves only as a 
separator. The elevation angle 
will be shown as zero if the 
satellite is below the horizon. 

Approximately thirty 
seconds of each minute are 



used in calculating and for- 
matting new data, and the 
remaining thirty seconds are 
devoted to six S-second data 
displays, which are dis- 
tributed throughout the one 
minute period. If your calcu- 
lator runs the program cor- 
rectly but completes a loop in 
less than sixty seconds, add 
one or more PAUSE com- 
mands at the end of a display 
to pad it out to a full minute. 

After the program is run- 
ning correctly, record it on a 
program card and save the 
•contents of the registers on a 
second data card. ■ 



Program IXsiing 



STEP 


KEY ENTRY 




KEY CODE 


COMPAENIS 


STEf 


J(EY ENTflY 


KEY COOP 


COMUEMTS 


STEP 


KEY ewinv 


•^eY CODE 




COMMENTS 




STEP 


KEY^NTRV 




KtY CODE 


COJUMEMTS 


oa- 






I>ArA 





JS3P z 








SIM 






7j^ '- 


^jf^ 




■■^'^i> sri-^'^ iT. 










OS. 








.3 5^. 










^^,_ 


4- 


— 




H 


^I lA 






— 




S(N 






K; 






3T0 7 






lie I 




- h- 






+ 






STo o 






^ 














srof: 






i- 






Si-O 




IK 


RCL 4- 






ffSBS 






STO Z 






RC1_8 






^[vJ 






G-roA 




...j^iE^,^^ 


S/'S &^i^<\ 


fp^ 


-...a 

stoc 








SIM 












>tL^LS 




£>Ar^ ^i^iS'^'^^r 








w 






■QCLS 






FiTLC 








3rl 






3J-J-I 






r.ss 




ISO 


-Je- 






RfS 






2.TO A 












er ^1 






V-LBt 7 




o™ 


BCL"; 






cos~i 






-*iL,ftt^S. 






sro^i. 






ect.3 






F? £ 






RdcZ 






sro + 2 












^t04- 






X^ o 






^acA. 






RCI 






!^CL3 






P/-3 






^ 






* 




no 


iC/Y 












«,TC+ 1 






COS 
















u?& 


»CL 1 












* LBL+ 












RCL5 






Cos 






s-ro P 














.f.<r 






-;■ 






fiSRfi 




iV:; 














?tP T 1 






C05.-1 






E?^i a ' 














S60 


ECX 






CCLS I 




"' 






-R£L.a^ 






4 






+ 












KCL3 








+ 



















«' 






RCL ! 




Lie 


^ 












5.-0+7 






-i- 






RCE.© 










MO 


RCL7 






STo FS 


















? 






asB S 






+ 














4. 






^-fii3__ 










ek; 







<,<T 






ecti? 






CQS 










STo-a 




OM 


irrr 7 






K 












Ss-hA.^. 












Rfi.;^ 












D5FO 






S/A/ 




















PftUSE 






>f<-D 






Jv 












_£iJ.^L 






^Fl>. 




UCi 


TArJ-1 












PAUSE 






Sl^-I 






x^a 










t.-.P 


RCI.7 






Ca^ 






GT0 3 












H.MS 






AClB 






3 












PSpa 




- 




^•a^ 











;in 








RTbJ 




_ . 


. 




H 






jf/r 












xiei, B 






100 


i 


















o^/?/?- c^-i y^- 










1 






Co/s 






«LBL ;5 












. 6*aT 






■Jf 


















RfNf 






vtrie 


















* L;BL A 








3/^ 




163 


p/^ 












fiSB2 






KiA 




WCUEL 










fi.Sf. 


lES 






.'il'J 






:^ <0 














a; L & 






* 






O 












«t I 


- 






+ 










> 








« 






ric^-i 






:? 












KdLT 




110 


STC14- 
















-f 






&SES 






RCL D 










<,-n o 




f?CLA 






I'vlT 












REGJSTERS 






LABELS 


FLAGS 


SET STATUS 








2 OHS IT 13 




B^ec 


E '/e= 




&/A/^ij-V.= 




'^ T/SACK 


B C 









FLAGS TRPG DISP 


sc 


S1 


--, '^ 3^o 


'^AXC 


3S * - 
3fC 


OAST'S 




3?SS' 




" 


'^ 


= 


a 




^ 


CI LI n 

2 D 3 


GRAD ;: 

RAD n 


FIK PT 

SCI 1 

ENG L"j 


5 


■ 


2 


3 


" 


z 








O^ AV^^ 




^^T"- ^ 


•-S 


■- \ 


n 


^5,^r 5 


S^ 1 DIS 


fi^Y 


^.5 


- 1 


\ ^(A/C 


^ £Cly 










9 


z 



65 



Logical Thoughts 
About OSCAR 



-- meaningful to computers! 



V/m. Denisoij Y. Rich OA6AD 
CasiJia 75] 
Arcquip^f Peru 



Several months ago I re- 
ceived a free copy of 
Ham Radio Horizons and 
read the article about the 
OSCAR (Orbital Satellite 
Carrying Amateur Radio) 
satellites.' Up to that time, I 
had heard of OSCAR but 
supposed I would need a 
good deal of auxiliary equip- 
ment to access the satellites. 
However, according to the 
author, my trusty SB-102 
should have been able to hear 
either of the OSCARs. The 
only problem was when to 
listen. Since the maximum 
exposure (during an overhead 
pass) is a little more then 20 
minutes, and there are, at 
most, four favorable passes 
per day, random listening is 
definitely out. 



At the time, I recalled that 
the ARRL was publishing 
AM SAT-supplied^ equator 
crossings for the OSCARs in 
daily CVV bulletins. A day of 
poking around in the QRIM/N 
on 20 (why does everyone 
tune up on 14.080?) netted 
me a dozen crossings, and, 
with a dandy desk calculator, 
I was able to fill in the gaps 
and make several days of pre- 
dictions. 

Shortly after, I heard 
OSCAR 7 on one of the 
passes I had predicted, and I 
was hooked. I also heard half 
a dozen or so stations 
working through the satellite 
and am now working on a 
solid state, 2 meter CW rig 
(you convince yowr wife you 
absolutely must have a new 
$700 transceiver, so you can 
talk to a satellite) and some 
sort of antenna to go with it. 

But, if I can do these 
predictions on a desk calcu- 



lator, why can't I do them on 
a computer? 

At work (oddly enough, a 
satellite tracking facility t)f 
the Smithsonian Astro- 
physical Observatory), we 
have a NOVA 1 200 minicom- 
puter." Since this machine is 
available for some time each 
day, the next step was to 
write a prograin to predict 
successive OSCAR passes. 



Language 

Although we have two 
more efficient languages avail- 
able, I chose to use BASIC^ 
(DGC Extended BASIC as 
modified by C0[^ ) for three 
reasons: 

1 . BASIC is one of the 
most easily understood 
languages available, its clarity 
far outweighs any lack of 
speed, especially for the 
beginner. In this case, speed is 
no consideration anyway, be- 



cause the actual computation 
takes only a few milliseconds, 
with most of the program 
time spent in controlling the 
teletypewriter output device. 

2. BASIC is widespread. 
Most school computers, be 
they in high schools, colleges, 
junior colleges or even in 
grade schools, run in BASIC, 
in addition to other lan- 
guages. The chances are good 
that, if you have ever used a 
computer, you have pro- 
grammed in BASIC. 

Check with your local 
school board or with the 
science and math depart- 
ments in your school system. 
If the school does have com- 
puter facilities, this might 
make a nice tie-in for a new 
educational use for OSCAR. 

3. IVlany advertisements 
for microprocessor/computer 
systems list BASIC as a 
ready-to-run language, either 
supplied or available as an 
option. 

Programming 

For any nontrivial pro- 
gram, a flowchart is almost 
essential and is an easy way 
to block out the job. The 
flowchart will usually suggest 
ways of breaking up one large 
job into several smaller ones. 
Fig, 9 shows some commonly 
used flowchart symbols and 
their meanings. 

In the main chart for this 
program (Fig. 1 and Fig. 10, 
lines i through 299), each 
phase of the program is repre- 
sented by a separate block. 
Some blocks stand for a 
single instruction, but most 
stand for two, three, or more. 

Fig. ■ 1 begins with the 
block RUN and "flows" in an 
orderly manner to the block 
END. Some of the blocks 
(SELECT A SATELLITE) 
stand for what are called sub- 
routines. A subroutine is a 
short program which takes 
care of some special job, like 
selecting the elements for a 
particular satellite. Usually, a 
subroutine is written because 
the same small job is to be 
performed several times, and 
there is no sense in repeating 
the same "code" over and 
over. 



66 



f ^coc J 



jsfi; =Tp Tig 




D? iHt f'LEI 




: IMPUTE 




F/^. /. Main program flow 
showing data entry points, 
computations, output points, 
and major subroutine calls. 

Quite often a stock sub- 
routine can be used in other 
programs with little or no 
modification. For example, 1 
have already used the 
"calendar" subroutine (7000) 
in two other programs. 

I like to use subroutines to 
make the big job smaller and 
easier. If all the subroutines 
used in this program were 
combined into a single pro- 
gram and flowchart, we might 
need a square meter of 
paper on which to draw it 
and, certainly, a tour guide to 
help us through it. 

An "ultimate" main pro- 
gram might even begin at 
RUN, consist of nothing 
more than GOSUB state- 
ments, and finaliy terminate 
with an END statement. 

To keep things simple: 

1 . Break up the big job into 
individual steps. 

2. Keep the "main" program 
and its flowchart in as 
straight a line as possible, 

3. Document your program 
with explanatory remarks 
wherever possible. If you de- 
cide to make changes in 6 
months, you'll be awfully 




Fig. 2. Subroutine 8000, which is used to select either a fiied 
satellite or a new, unfiled satellite. 



glad you have these notes. 

In BASIC, it is not neces- 
sary that line numbers fallow 
sequentially. The program al- 
ways goes to the next highest 
line number for execution 
(unless, of course, it en- 
counters a GOTO, GOSUB, 
or RETURN statement). 

I like to think of the avail- 
able program area (lines 1 to 
9999) as a notebook. Early 
"pages" are used for the main 
program, with plenty of 
blank pages left for later 
changes or corrections; later 
pages are used for sub- 
routines, filling the "book" 
from the back toward the 
front. If yo!j put everything 
in the front of the "book," 
and then have to rewrite 
some section or insert correc- 
tions, you will have a major 
rewrite job on your hands 
because of the lack of vacant 
line numbers ("pages"). 

Equator Crossings 

The objective of this pro- 
gram is to produce OSCAR 
equator crossings (time — UT, 
longitude — W), based on 
reference orbits (initial condi- 
tions) supplied by AMSAT 
viaWIAW. 



In the following discus- 
sions, no attempt is made to 
explain, in detail, the 
workings of BASIC. It is 
assumed that, if you have 
access to a computer and 
BASIC, you also have access 
to any necessary "biow-to- 
use" manuals. 

Lines 1 and 2 (Fig. 10) are 
self-explanatory. Lines 10 
through 39 are used to set up- 
several constants and an ar- 
ray, all of which will be used 
later by different sections of 
the program. Lines 40 and 41 
are the "TITLE" block of 
Fig. 1, followed by line 55, 
which sends us .to the 
"SELECT-SATELLITE" sub- 
routine, beginning at line 
8000. 

This subroutine (lines 
8000 through 8201 and Fig. 
2) tells us which satellites are 
preprogrammed and asks 
which we want. Lines 8025 
and 8030 direct the flow to 
the appropriate set of ele- 
ments, each of which is ter- 
minated by a GOTO 8200, 
Line 8200 announces the 
chosen satellite, and 8201 
contains the RETURN state- 
ment, which must end all 
BASIC subroutines, and 




Fig. 3. SubrouUne 9000, 
which is used to enter the 
reference day and position 
- for the selected satellite. 

which transfers control back 
to the main, prograin. Lines 
-S063 and 8083 set the state 
of a flag, F1, which will be 
used later to help format the 
printed output of the pro- 
gram. 

If the tests in lines 8025 
and 8030 fail, then line 8040, 
the next instruction in se- 
quence, sends control to line 
8090. These are self-explana- 
toiy, except for line 8140, 
which converts the westerly 
drift, entered by the opera- 
tor, to easterly drift, the form 
which will be used by the 
program in its calculations. 
We will, of course, convert 
the output back to westerly 
degrees before printing. 

New satellites may be pro- 
grammed by inserting an ap- 
propriate test in the decision 
chain, starting at line 8025, 
and, of course, a block of 
elements ending with GOTO 



67 



LET £ =SV6Q 



1 


m 


IN 


•SU^Cil 




„,- 


r,., 


Kiiy?-! 



F/£?. 4, Subroutine 7500, in 
reality only one line long, but 
shown liere as 4 separate 
steps in the interest of clarity. 
This subroutine converts 
integer hours, minutes, and 
seconds into decimal parts of 
a day, and then adds this 
number to the current day. 

8200. One would also change 
line 8000. The element block 
may go anywhere in the sub- 
routine, provided that the ele- 
ments end with GOTO 8200. 

Now, go back in the main 
program for a second. Line 
70 transfers control to the 
subroutine at line 9000 (Fig. 
3). 

Lines 9000 to 9040 are 
self-explanatory. Line 9045 is 
included because time is only 
requested to the nearest 
minute, but, since seconds 
(SI) are used in the calcula- 
tions, SI must have some 
vaiue. !f, later, you want to 




Fig. 5, Subroutine 8300, which sets up the flag, Fl , for later 
use by the output routine. In the event that the unavailable 
days are to be suppressed, the day of the week for the 
reference orbit is entered here. 



include seconds as an input 
variable, tlie only change 
needed will lie to delete line 
9045 and add SI to the input 
lines, 9035 and 9040. SI is 
already included in all perti- 
nent calculations. 

Once again, line 9053 con- 
verts west longitude to east 
longitude, just as was done 
back at line 8140. 

At line 9065, we find an- 
other subroutine call. Sub- 
routine 7500 (Fig. 4) is a 
one-liner which turns sec- 
onds, minutes, and hours to 
decimal parts of a day. 
"Decimal" days are by far the 




^- 


FEU 


LIMIT 




'C 


30 






-- 


hl; 


■'" 






1 







Fig. 6. Subroutine 700Q, the calendar subroutine which takes 
care of advancing the month and year, when required. This 
subroutine also takes into account the possibility that the 
current year is a leap year and that, therefore, February must 
have 29 days instead of the usual 28. 



simplest way of keeping time 
in a program! 

After returning via line 
7550, we are immediately 
sent, by line 9070, to sub- 
routine 7000 (Fig. 6). This is 
the calendar manager and is 
perhaps the most complex 
subroutine in the program. 
What does it do? 

First, it checks to see if 
the current day is still inside 
the current month. If it is, 
then control is passed right 
back to the calling program'" 
If not (say we had typed FEB 
29), the subroutine 
checks to see if the current 
year is a leap year. If this is- 
so, the limit day of February 
is set to 30, if not already so 
set, and the current day is 
again tested at line 7020 to 
see if it has become a legal 

( 950O j 



Fig. 7. Subroutine 9500, 
which prints headings for 
each day's passes. These 
headings will be printed even 
If the output for a particular 
day is suppressed. 



day by virtue of the limit 
change. It is the accounting 
for leap year that makes this 
subroutine so complex. With- 
out !eap years, the only 
branch would be the first 
one, at line 7020, 

If the current day stili fails 
the test at line 7020, then we 
must move oji to the next 
montJi, so lines 7038 through 
7060 are exectfted, and a 
return is again made via line 
7020. This last test is cheap 
insurance against having 
created an illegal day. 

If line 7045 finds month 
(M) value greater than 12, It 
increments year (Y) and re- 
turns via the legal day test 

Note that, if the test 
"L{2)=30?" is not included at 
line 7085, one logical 
course of action, after finding 
that the month is February, 
would be to set the limit to 
30, then reenter at line 7020. 
This is okay until the day gets 
to be February 31 or ^eater, 
at which point the program 
has no way of breaking the 
loop and performs: (LEGAL 
DAY?) - (MONTH iS FEB?) 
- (SET LIMIT = 30) - 
(LEGAL DAY?) - (MONTH 
IS FEB?) - etc., - etc. . . ., 
until the cows come home. 
Flowcharts are a great help in 
avoiding this sort of bug. 

Now let's go back to line 
9073 — that is, jlist following 
the subroutine call to the 
calendar manager. Re- 
member, we are entering 
initial conditions for a pre- 
diction run. Only one more- 
parameter needs to be 
checked — the flag, Fl. This 
is done at Sine 9073. Sub- 
routine .8300 (Fig. 5) is 
called, if necessary, and asks 
if you want all crossings or 
only those available for use. 
So far, only OSCAR G has a 
serious restriction, but, since 
any satellite might have one, 
the option is included. Re- 
turn is made to the calling 
subroutine and then to the 
main program via line 9075. 

Lines SO through 130 of 
the main program are self- 
explanatory. Line 140 sends 
us to subroutine 9500 (Fig. 
7), which will print the satel- 
lite number and date for each 



68 



new day predicted. 

The actual calculation 
loop, lines 150 through 195, 
is executed (13 x 1)/S times. 
See iines 80 through 100 for I 
and S. Subroutine 7600 (Fig. 
8) is the output routine and 
immediately calls the 
calendar (7000). Subroutine 
7600 then checks to see if 
this is a new day (line 7612), 
and, if it is, calls for a heading 
to be printed. 

The decimal day is con- 
verted to a day, hour, and 
minute (lines 7682 through 
7691). The orbit number and 
time are printed (lines 7693 
and 7696), and the longitude 
is converted to west and 
printed by line 7698. 

The odd decision chain, at 
lines 7625 through 7635, 
tests the value of Fl , which 
was set up back at lines 8063 
and 8083. If Fl is nonzero, 
only the "available days" are 
printed. More available days 
couid be added to the chain, 
if needed. 

Note that, since the "new 
day" test (line 7612) is done 
before the test of Fl (line 
7620), a heading will be 
printed for every new day, 
even though the passes for 
that day are suppressed. The 
heading doesn't take much 
paper ancf lets you see at a 
glance what the program is up 
to. 

Fig. 11 is a sample run. All 
human typing is underlined. 
Computer output is not. 

Simplicity or Flexibility 

A program such as this 
requires a lot of work to 
write, especially when com- 
pared with the actual amount 
of calculation it does. But it 
takes me several hours to 
prepare 30 days of predic- 
tions, not counting my pen- 
chant for arithmetic errors, 
while the machine can com- 
pute and print the same 
number of predictions in 
about 20 minutes^ with no 
errors, provided it is pro- 
grammed properly. Thirty 
days comes to about 400 
crossings. 

The amount of work re- 
quired to prepare this and, 
perhaps, most programs can 



be justified only if an equiva- 
lent or greater amount of 
time can be saved later on. It 
is for this reason that the 
program was made flexible. A 
simpler program would not 
have options like the choice 
of satellites preprogrammed, 
entry of trial satellites, and 
the like. For a little extra 
work now, I have a program 
which allows me to file a new 
satellite in a matter of 
minutes or to run a trial on a 
new satellite at the cost of 
entering its period and west- 
ward drift. I can easily sup- 
press output of any day's 
passes, and the days to be 
suppressed can be changed by 
changing only one or two 
iines. 

When OSCARs 8, 9, and 
10 come along, this program 
will be running within 
minutes of my receipt of the 
necessary data. 

Speaking of data, you may 
get it from a magazine article, 
as I did, or you could com- 
pute it, if you know any two 
reference orbits, 0RB1 and 
0RB2, It helps somewhat if 
the two known orbits are a 
few days apart 

Period = p = (TIIVIE2 - 
T1ME1)/(0RB2-0RB1) 
Drift (W) = T = (LAT2 - 
LAT1)/(0RB2-0RB1), 

where TIME and LAT are the 



( 7500 j 




( RETURN J 

Fig, 8. Subroutine 7600, which causes a heading to be output, 
if necessary, and then decides which, if any, of the crossings 
will be printed. 



initial conditions for two 
crossings, and ORB1 and 
ORB2 are the orbit numbers. 
One further improvement 
might be to add a longitude, 
test to the output routine, 
such that only passes which 
will be "visible" from your 



station will be printed. This 
would drastically cut the 
total running time. 

Parting Thoughts 

Keep track of the re- 
siduals, or the differences in 
time and longitude,-;between 



CZ) 



Usually used to signify a start point (RUIV!) or an END. Also used far 
entry and exit poirrts of subroutines. 

This symbol always signifies a decision point. Usually the branch paths 
run out from the side of the diamond; however, this is not necessary if 
the paths are clearly marked — yes, no, true, or false. 

This and the following symbol describe any "process." A process may 
be a GOSUB, GOTO, LET, PRINT, or any other operational 
instruction- 



Output, in the form of a printed document. This symbol may be used 
for either teletype or line printer output. 

These arrows indicate program flow. They are one-way only, like 
diodes. Once flow has passed through an arrow, it may not go back. In 
this example, there is an insolvable problem in that all four arrows 
point into the intersection- There is no exit! 



Input, usually from a keyboard terminal. 

j 7 Comment, either an output from the program or an explanatory block 

/ / for the programmer. This symbol does not have to represent a section 

[ / of the program. 

Fig. 9. Some of the symbols used in flowcharts and some of their possible meanings. 




LONGITUDE-WEST" 



0«ei REP! HAIH MOGBAPI: COrPUTEE AHD PBIBTS 

eeez kfm equator crossings eor oscsr sstfllites. 

BBI0 DIM HIE 1 ,f1StJ61,U* ffill 

eeil DIM Yt[lI,D$tJ],«$Tgl 

eeiS DAT* JZ ^9,J2,JI,32,Jl,ja,J£,Jl,JS2,31,J2 

BBIT LET Ui-'' SUNMONTUEWEDTHUFRISAT 

PPirB LET (It-- JANFEBilSHAPRMAYJUNJULAUGSFPOCTKOVDEC- 

0H20 FOR 1=1 TO 12 

8025 READ Lfl] 

ease next l 

0BJ8 LET At=-8 JUNE" 

0039 LET Vig.lJ 

Il0^a PRINT " EOUflTOR CROSSIHGSt UERSIOM"-U- 

9041 PRINT " OF -;A<;t" 1977 [COI-XBflSIC 1" 

ee55 GOsuB e(i0<! 

0(*70 GOSUB SB00 

0080 PRINT - HOV MANY DAYS OF PREDICTIONS"- 

0BB5 INPUT I 

0050 LET I =1*1 J 

Bes5 REM ORBITAL INCREMEWTi IrEACK, e=EVEI)v OTKER 

0100 LET S=l 

0!B5 RE« CONVERT P FKOfl MINUTES 70 DAYS 

eilB LET f-P/St/SA 

aiZ0 PR!NT 

0130 PRINT " ORBST TlnE(UT) 

01 « SOSUB 95B0 

01 50 FOR JiBTO ISTEP S 

0155 LET V=V+ S 

0160 LET Z: Z+ T*S 

0165 LET r = (Z/JS0-I»IT(Z/JSe))*360 

0170 LET JJ^D+F** 

51 85 G0SU3 7S00 
B15! NEXT J 
0239 END 

7000 REN Hi SUBROUTlNEt CALENDAR 
7B80 IF D=»LtMlTHEN GOTO 7035 
7*25 GOTO T095 

7ej5 IF Y/4-INT(Y/4)=0THEN GOTO 7070 
70JS LET D=D-L[M1+! 
7040 LET r.-n+i 

7045 IF^!=<|^ THEN ROTO 7020 
7e5f LET Y: Y+1 
7060 LET M=M-12 
70S5 GOTO leze 
7070 IFM;2 THEN GOTO 7*85 
7075 LET 1.12 ]r29 
70aP GOTO 7038 

708! IF L!Z 1:30THEN GOTO 703B 
7090 LET L[2 1=30 
7055 GOTO 7820 
709S RETURN 

75ee LET n=Di+(Hi*(Ni+si/se)/s05/ai 

7 550 RETURN 

7Se« GOSUB 7CI00 

76)2 IF INT(D)=D1THEB GOTO 7S20 

76! 5 LET DJ =INTt D) 

7616 GOSUB 9 5eS 

7SI 7 LET U=U+1 

761S IFUz-cTTHEB GOTO 7620 

7S1» LET U = I 

7SZ0 IF FJzeTHEN 30T0 7S32 

7ffiJ LET U0=S* l!-2 

7SE4 LET U1:S* U 

76E5 IF US(UB,UJ1=- HON" THEN GCTO 7682 

7S3P IF U$[UB,UJ J =" THU'TMEN GOTO 7«a2 

7635 IF UirflB.Ul 1 =" EAT" THEd GOTO 7S82 

76B0 GOTO 7S99 

TSa2 LET Dl = INTCD) 

7S«6 LET HJ -<D-D1)»24 

7690 LET III=IHTC(Hl-INT(HI))*6&t.5) 

7e»L LET HUINTtH!) 

7693 PRINT W, 



7«96 
7(»7 
7698 

7S99 
8000 
802(1 
802 5 
8030 
8fS5 
S04C 
8045 
8050 
8055 
8C«e 
8063 
S0S5 
80 T« 
8075 
808* 

8035 

8090 
8095 
SI 00 
SI20 
3125 
SI 30 
8135 
l?!4« 
SI 45 
8200 
3201 
S300 
8325 

sjsa 

8335 

ff338 
83« 
834 5 
83fl7 
8350 
3360 
8365 
8370 
8375 
S380 
8364 
838S 
3388 
3190 
8392 
8399 
90011 
9015 
9*20 
9K5 
9*30 
9035 
9040 
9fl45 
9043 
9050 
9053 
9055 
906* 
9065 
9070 
9B7J 
9075 
9580 
951 5 
95 50 



"««#", HI*ieB+Nl; 



ENTER DESIRED SATFLLITF; 



IS HOT ON FILE. TYPE TO RUN A TBIAL" 



Fig. 10. A complete listing of the program. 



PRINT USING 

PRINT ", 

PRINT USING ■«*.»",3«0-7+.B5 

RETrmH 

PRINT - OSCAR 6 AND 7 ARE ON FILE 

INPUT 

IF OrSTHEN GOTO 8050 

IF 0=7THEN SOTO £070 

Rtrt DE.'^AULTt BE9(JISTED SJITELLITE SOT 0» FILE 

GOTO 8090 

REM ELEMENTS FOLLOW! 

REW ***** OSCAR -6 ***** 

LET P=I1*. 994*0 

LET T=-?,8.748S+« 

LET FU! 

GOTO 8200 

REM ***** OSCAR -7 ***** 

LET P = l 14.945+0 

LET Ti-38.73ffl+e 

LET Fl=fl 

SOTO 3200 

PRINT ■ QSCAR'tO; 

INPUT 

IF 0>BTHEN GOTO 802! 

PRINT " PERIOn (MINUTES)-, 

INPUT P 

PRINT " DRIFT fOEG VFET) ", 

INPUT T 

LET T=T*-1 

LET Fl =0 

PRIST - PREDICTIMG FOR OSCAR-(0 

R FTUH N 

PRINT "SUPPRESS UNAVAILABLE ORBITS(Y/N)" i 

INPUT Yt 

IF Yt»-<" Y" THEN GOTO 8340 

LET Fl =1 

GOTO 8550 

IF YS>-*- N 

LET F150 

GOTO BJ99 

PRINT " REFERENCE DAY ■• , 

INPUT K 

FOR IrlTO 7 

LET U=I 

IF DJ, :US[3* I-a,3*IlTHEN GOTO 8595 
NEXT I 

PRIHT - LECAL WYS ARFi "t 
FOR I-ITO 7 

PRINT US r3*I-a, 3*11 1" "l 
NEXT I 
GOTO 8358 
RETURN 

PfllMT - REFERENCE ORBITi- 
PRINT - YY , MM , ro ■ ",■ 
INPUT Y,M,D1 
IF M=BTHEN GOTO 9015 
IF Dl =0-iHEN GOTO 9015 
PRINT " HK , MM 

INPUT HI ,N1 ""— . 

LET SI =0 

PRINT - LONGITUDE < IKGR-WEST)", 
INPUT Z 
LET Z=i60-Z 

PRINT " ORBIT NUMBER ", 
INPUT V 
GOSUB 75Bf 

Gos'jB Teea 

IF Fl :1TWEN GOSUB 8300 

RETURN 

PRISiT 

PRINT' OSCAR";Oj" "?!St3* n-2 ,3*M ) ! !NT( D) ; Vi I 900 

RETURN 



WEN GOTO 8325 



your predictions and the 
W1AW bulletins. I once pre- 
dicted OSCAR 7 for 30 days, 
only to discover later that 
there was a 10-minute bias to 
all the times because the 



reference orbit had been 
wrongly copied from WIAVV. 
Typical residuals, over a 
30-day prediction cycle, have 
been ±1 minute and ±.1 de- 
gree of longitude. These dif- 



ferences creep in mainly be- 
cause the AMSAT/WIAW 
bulletins only give time and 
longitude to these accuracies. 
We cannot expect the pro- 
gram to be more accurate 



than the data given it. 

This progi-am is only one 
way of reaching the stated 
objective. There are usually as 
many programs per problem 
as there are programmers 



EoBJJ^OR CROSSINGS; VERSION 2.13 OF 8 JUNE 1977 {COI-XBASIO 
OSCAR 6 AND 7 ARE ON FILE, ENTES DESIRED SATELLITE! ? 7 
PREDICTING FOR OSCAR 7 



REFERENCE ORBIT: 




TY , MM , 


DD 


? 7T.5.30 


HH , MM 




7 »,jT 
7 ^.,6 


LONaiTUDE 


( DtOR-KEST) 


ORBIT NIMBER 


T Tl6fl5 


HOW W«»Y MYS OF PREDICTIONS 7 2. 


ORBIT 


TlMEtUT) 


LONGITUDE- WEST 


OSCAR 7 


WAY SB 


J97T 


11606 


232 


91.4 


116*7 


427 


120.1 


11608 


€22 


148.9 


11609 


817 


177.5 


list* 


1012 


206.3 


llSIt 


1207 


23 5.1 


11612 


1402 


2«3.8 


1ISI3 


1557 


292.5 


HSU 


1751 


321.3 


11 SI 5 


1946 


350.0 



1 1«1« 


2141 




IB. 7 


11617 


2336 




47.5 


OSCAR 7 


MAY 31 


1977 




1 1618 


131 




7S,2 


1161 9 


32 6 




105.0 


11620 


521 




US. 7 


11621 


716 




162.4 


I1S22 


911 




191.2 


11623 


11*6 




219.9 


11624 


1301 




248.6 


11625 


145S 




277.4 


1IS2S 


165! 




306.1 


11627 


1846 




334.8 


11628 


2*41 




3.6 


11629 


223S 




32.3 


OSCAR 7 


JUN 1 


1977 




1 1630 


30 




61.1 


1 1631 


22 5 




89.8 


11632 


420 




1IB.5 



END AT «299 



Fig. 11. A sample run for OSCAR 7. Human input to the program is underlined. Everything else is the product of the program. 



70 



attacking the problem, in this 
case, for example, certain sec- 
tions of the coding were 
made to ta.i<e up several lines, 
where only one line was 
really needed. This lias re- 
sulted (I hope!) in greater 
clarity at the expense of 
space. Why not try improving 
this program? 

Not all BASIC versions are 
identical. Make sure the 
Features I have used are avail- 
able in your version of the 
language, before writing a 
stiff letter to the editor. 



Important note: When 
listing a program, this par- 
ticular version of BASIC 
often inserts phantom spaces. 
These are only important in 
the following lines: 

Line 17 must begin 
"SUNMON..." with no 
spaces between the quotation 
marks and SUN. 
". . . FRISAT " does include 
3 spaces following SAT, and 
then the quotation mark. 
Line 18 is similar to 17 and 
must begin "JANFEB . . .", 
without spaces after the lead- 



ing quotation mark. There are 
no spaces following DEC. 

Lines 7625, 7630, and 
7635 are similar in that the 
test day, for example 
"MON", must be enclosed in 
quotation marks without 
spaces as "MON"/THU", or 
"SAT". 

Lines 8330 and 8340 are 
the same; the Y and N must 
be entered as "Y" and "N", 
without enclosed spaces. 

All other blank spaces in 
Fig. 1 are not critical and 
may be inserted or deleted 



according to your whims or 
the requirements of your 
flavor of BASIC." 



References 

1. Hsm Radio Horizons. March, 
1977, pp. 18ff. 

2. Radio Amateur Satellite Cor- 
poration, P.O. Box 27, Washing- 
ton DC 20044. 

3. NOVA >s a registered trade- 
mark of the Data General Corpor- 
ation (DGCl, Southboro MA 
01772. 

4. BASIC was developed at Dart- 
mouth College. 

5. Computer Operations, Inc. 
(COD, Beltsvilie MD 20705. 



RTTY Loop 



1 hope you enjoyed the special 
RTTY issue! Now that you are com- 
pletely ready to operate, a few hints 
and suggestions are in order. Required 
equipmsnl is a printer/keyboard com- 
bination (Model 15), a loop supply, a 
terminal unit, and an AFSK generator. 
I assume that you already have a 
transceiver capable of operating SSB 
on the low bands, tet's get started! 

RECEIVIIMG i^TTY 
By convention, RTTY operators 
congregate on certain areas within the 
CW portion of the band in question. 
There is activity on both 80 and 20, 
not much on 40, 15, or 10. Eighty 
meter activity is usually found around 
3615 kH2 and up. Twenty meter 
teletype freaks sre found from 14.08 
to 14.1 MHz. Sideband conventions 
are reversed on all HF bands extept 
80. Therefore. RTTY is received and 
transmitted on lower sidebarxi on 
twenty — voice is upper. On 80, SSB 
and RTTY are both transmitted on 
the lower sicJeband. 

In order to properly receive RTTY, 
the signal must be carefully tuned. 
Allow your transceiver to perl< for an 
hour or so before tuning up the first 
time. An audio sample must be 
coupled to the TU ... normally 
through a matching transformer. 
Many of the popular TUs such as the 
HAL ST6 and Flesher DM-170 re- 
quire a 500-600 Ohm feed for proper 
operation. In a pinch, however, the 
TU can be paraileled across the 
speaker line. There are two common 
metiiods for tuning a RTTY signai. 
The first, and easiest, method employs 
a meter. The TLI meter indicates a 
steady value v/hen the signal is 
properly tuned — if not, it will jump 
randomly in the presence of RTTY or 
CW. Carefully tune the receiver until 
the meter is steady . . . it's best to 
start out on a strong signal! Consul; 
the operating instructions for your 
particular TU for specific details. The 
second tuning method uses an oscil- 
loscope with the horizontal sweep 
disabled. Almost aU TUs have "scope 
output" terminals which allow the 
mark and space discriminator output 



to be coupled to the scope. When 
receiving a RTTY signal, a pattern of 
crossed ellipses or circles will be 
present. The technique is to tune the 
receiver until the elliptical patterns are 
as large as possible, and as close to 
right angles to each other as possible. 
Most modern TUs have both scope 
outputs and meter tuning; try the 
meter method until you have the hang 
of tuning RTTY. 

At this point, you should be able to 
copy amateur QSOs. Saturday after- 
noon is the best for 20 meters — if 
you are lucky you'll hear Ricky 
WA0CKY transmitting one of his 
classic RTTY pix! You shouid also 
hear (see!) stations calling CQ. If 
you're ready to ansvjer, read on! 

TRANSMITTING RTTY 
Transmitting is simple. The output 
of your AFSK generator is connected 
to the microphone input of the SSB 
transceiver. When the loop is keyed, 
either by the keyboard or tape reader, 
the AFSK oscillator converts the 
Baudot pulses into frequency shifted 
mark and space tones. A caution is in 
order at this point: RTTY, like CW, is 
a continuous duty transmission. 
Unlike SSB, RTTY imposes extra 
strain on the final of your transmitter. 
It is wise to derate SSB ratings by a 
factor of four — if your rig is rated at 
200 Watts PEP, do not allow the 
continuous RTTY output to exceed 
about 50 Watts. Save a tube! You will 
soon find that most RTTY operators 
do net use high power ... like CW, a 
bit goes a long way. In most cases, 
200 Watts and a beam will do the 
trick. I run 75 Watts, and have needed 
more on few occasions. 

When using a standard SSB trans- 
ceiver, use 170 Hz shift. This insures 
that the audio tones are well within 
the passband of your transceiver's 
fitter. It is possible when using 850 
shift to produce a secondary, and 
illegal, carrier. Most current activity is 
on 170 shift anyway. 

An aside: A good beginner's RTTY 
transmitter is an old Heath HW-32 20 
meter singlebander, popular a few 
years ago. This rig is designed for 



phone only service, but can be put on 
RTTY (or CW) fay changing a single 
crystal. 1 performed this modification, 
and threw in a new filter crystal to be 
safe. The HW-32 will put out 40 Watts 
continuously, using sweep tubes in tiio 
final. 



KEreOARO 



Although this issue marks my last 
as Executive Editor of 73, I'll slill 
look forward to seeing you on 14.090 
or 3615 in the evening! 

John iWolnar WA3ETD 
Executrve Editor 



nun 



Ir 



LOOP 
SUPPLY 



TERMrJ^flL LMT 



~lh 



120V AT.06A 



"^ 



EAKER Tt 



^ 



t 



RECEIVE AUDIO 



J^ 



«500 OHM 

aUDlO 

TRANSFORMER 



SSB TRA^£CCW£?i 



t 



^* 



- ."iKSK TO 
MICROPHONE 
JICK 



Fig. 1. 




Many modern terminal units use a merer for tuning. A steady value indicates a 
properly tuned RTTY signal. Once the signal is tuned, the printer can be 
activated. The TU pictured is the HAL ST-SOOO. 



71 



Jack Colson VJ3TMZ 

RFD 3 

Mt. Airy TAD 21771 



OSCAR DX 

--a new challenge 



At one time or another, 
each of us has experi- 
enced difficulty in working 
DX stations because the HF 
propagation has been poor. 
We now have an alternative. 
With amateur satellites it is 
now possible to communicate 
consistently with stations up 
to 4500 miles away and 
predict exactly when they 
can be worked without the 
propagation problems in- 
curred at HF. 

A number of welFknown 
HF DXers are now quite 
active chasing DX via amateur 
satellites. In the United 



States, in less than two and a 
half years, Ben Stevenson 
W2BXA has worked 86 
countries via satellite. 
Actually, Ben and Pat 
McGowen G3IOR are having 
a battle to see who will be the 
first to work DXCC via satel- 
lite. Pat has at least 86 coun- 
tries worked to date. Bill 
Hunter K4TI did a study 
several years ago and con- 
cluded that DXCC was 
possible via the present 
OSCAR sateilites. Today with 
OSCAR 6 and 7 it is possible 
to communicate with 
amateurs in Europe and 



Africa every morning and 
early evening. On subsequent 
passes, amateurs in South and 
Central America as well as the 
Caribbean and Asia (AU9 and 
0) are within range. Between 
0300 and 0500 GMT the 
Sateilites are passing over 
California, which brings the 
KH6s in range. And we can 
work these DX stations every 
day, day after day. In fact, 
when HF propagation distur- 
bances occur occasionally, 
satellite communications are 
even enhanced. 

As a matter of history, in.. 
mid-October, 1972, the first 




Two 14 element KLM beams for 2 meters and a 432 MHz KLM beam for satellite DX In use at 
W3TMZ. 



long life amateur satellite wjls 
orbited. This satellite, 
OSCAR 6, has provided many 
new aspects to DX chasing, in 
mid-November, 1974, a 
second long life satellite, 
OSCAR 7, was orbited. It has 
provided even more DXing 
activities. 

OSCAR 6 contains a 2 to 
10 meter transponder with a 
100 kHz bandwidth. 
Specifically, the input fre- 
quencies are 145.90 to 
146.00 MHz, which translates 
to 29.450 to 29.550 MHz 
respectively. For normal com- 
munications, a power of 
approximately 100 Watts 
effective radiated power 
(ERP) provides a satisfactory 
return signal on the 10 meter 
downlink. For DX chasing, 
one should be able to access 
the satellite when it is near 
the horizoii; to be consistent, 
an ERP of 1 kW is recom- 
mended. To keep the AIVIS.AT 
officials happy and prevent 
overload of the satellite's 
receiver, one should adjust his 
ERP to maintain a reasonable 
but not strong return signal 
(comparable to other signals). 
Effective radiated power is 
defined as: matched power at 
the antenna terminal (s) times 
the antenna gain as a ratio. 
For example, consider an 
antenna with 1 2.5 dB of gain; 
this relates to a .power ratio 
of 1 7.78. If the power at the 
antenna terminals was 100 
Watts, the ERP would be 
1 778 Watts. 

OSCAR 7 has two trans- 
ponders. The first is similar to 
OSCAR 6 - this is termed 
Mode A. Its input frequencies 
are 145.850 to 145.950 MHz, 
translating to 29.400 to 
29.500 MHz output. The 
second is a 432 to 145 MHz 
repeater — it is termed .Mode 
B. Its frequencies are a 
432.130 - 432.170 input, 
translating to a 145.970 to 
145.930 output. There is an 
inversion in this transponder 
— as the operating frequency 
is increased, the output fre- 
quency decreases. This was 
done intentionally to reduce 
the effects of Doppler shift. 
Also, because of the inver- 
sion, a USi3 uplink (input) 



72 



AZ/EL 



VS 



Time 


AZ 


Min. 


Deg. 


7 


109. 


8 


102. 


11 


92. 


13 


78 


15 


61. 


17 


43. 


19 


26. 


21 


13. 


23 


3. 


25 


3S6, 



AZ/EL 



AZ/EL 



AZ/EL 



VS 



Time 


AZ 


Min, 


Deg. 


6 


118. 


8 


111. 


10 


101. 


12 


88. 


14 


70. 


16 


48. 


18 


28. 


20 


14. 


22 


3. 


24 


356. 



VS 



Equator Crossing Of --35.0 

EL 
Deg. 

1. 

6. 
11. 
17. 
20. 
20. 
17. 
12. 

6. 

1. 



Equator Crossing Of -40.0 

EL 

Deg. 

1. 

7. 
14. 
20. 
25. 
26. 
22. 
16. 

9. 

3, 



Equator Crossing Of -45.0 

EL 
Deg. 

-1. 

5. 
12. 
20. 
2S. 
34. 
32. 
25. 
17. 

9. 

3. 



Equator Crossing Of -50.0 

EL 

Deg. 

2. 

9. 
17. 
27. 
38. 
44. 
39. 
28. 
18. 

9. 

2. 



Fig. 1. OSCAR 6 and 7 tracking data for Washington DC and 
vicinity. (~) = west longitude; time = after ascending node 
equator crossing. 



Time 


AZ 


Min- 


Deg. 


4 


129. 


6 


124. 


S 


117. 


10 


107. 


12 


91. 


14 


6S, 


16 


41. 


18 


21, 


20 


7. 


22 


359. 


24 


353. 



VS 



Time 


AZ 


Min. 


Deg. 


4 


136. 


6 


131. 


8 


125. 


10 


114. 


12 


95. 


14 


63. 


16 


31. 


18 


11, 


20 


1. 


22 


354. 


24 


350. 



signal becomes an LSB on the 
downlink (output). 

For OSCAR 7, Mode A, a 
somewhat higher ERP is 
needed than with OSCAR 6. 
A good value is 10 dB more 



or 1 to 10 kW ERP, For 
IViodc B, an ERP of 80-100 
Watts will provide an ex- 
cellent return signal. 

Both OSCAR 6 and 7 are 
termed to be in sun- 



synchronous orbit — that is, 
they are available for com- 
munications at every point on 
the earth at the same local 
time of day. Each satellite is 
fixed in a near polar orbit 
approximately 900 miles 
above Earth, With such an 
altitude, it is possible to com- 
municate with the satellite 
when it is 2450 miles away 
from your location. This 
yields a maximum communi- 
cations range of 4900 miles. 
This can be extended con- 
siderably at times due to 
peculiar propagation 
phenomena which will be 
discussed later. 

Probably the most exciting 
facet of DXing via satellite is 
that you can operate every 
day and not be concerned 
with normal HF ionospheric 
problems. Once the satellite is 
within your range, you are 
ready. There are occasional 
VHF/UHF propagation dis- 
turbances which do affect 
communications, but not to 
the extent that a solar storm 
would have upon HF. An 
example: Last spring when 
HF communications were 
almost totally wiped out by a 
storm, many Europeans were 
wori<ed via satellite. 

Operating 

In order to operate via the 
satellite, one must know 
when it is available and iri 
what mode it will be for a 
given day. Orbital data is 
available from many sources. 
Probably the most convenient 
source is the W6PAJ hand- 
book. This book is published 
yearly and contains all revolu- 
tions for OSCAR 6 and 7*. 
The data is published in the 
form of date (GiMT), revolu- 
tion number, time (GIViT) 
that the satellite crosses the 
equator in an ascending node 
(south to north) and the long- 
itude in degrees west of 
Greenwich, With this data, 
one can compute when the 



*Skip Revmann W6PAJ, PO Box 
374, San Dimas CA 91773. For 
1977 handbool< send $5.00 non- 
AMSAT members; $3.00 AiVISAT 
members and a self-addressed 
3ticl<v label. 



satellite will be within his 
particular window. 

The next problem is where 
to point the antenna. Un- 
fortunately, this is difficult to 
accurately describe in a few 
words. Obviously it would be 
far easier to use a high power 
transmitter and almost non- 
directional antenna, thus 
eliminating the need for 
antenna directional data. Sad 
to say, high power equipment 
is rare and expensive. 

Generally, for ascending 
node revolutions, the satellite 
will rise from the south to 
southeast and go east of your 
QTH and leave in north- 
western azimuth. If the longi- 
tudinal crossing is west of 
your longitude, then instead 
of passing to the east, it will 
pass to the west. 

This is fine for azimuth, 
but what about elevation? !n 
most cases the operator will 
not be interested in elevation, 
because he is only interested 
in DX which can be worked 
principally when the satellite 
is near the horizon. The only 
reason for a DXer to use an 
elevation mounfi? to achieve 
practice in satellite usage and 
communicate with nearby 
amateurs. 

When OSCAR 6 was first 
launched, the VK amateurs 
generated AZ/EL data based 
on longitudinal crossing for 
"many major cities in the 
world, 1 personally use this 
table for my antenna point- 
ing. The second feature of the 
table is that it defines the 
satelli.t,e coverage for a par- 
ticular QTH. An example of 
this information for the 
Washington area is given in 
Fig. 1. 

To generate this data, a 
computer program (written in 
Fortran IV and adaptable to 
most machines), is available. 

Operating Tips for the Be- 
ginner 

There are several very 
important techniques that 
will be helpful. 

Pick an input/output fre- 
quency combination to which 
you can repeatedly reset your 
equipment, and always start 



73 




W3TMZ and his home brew 14 element KLM 432. 



operating from that Tre- 
quency. This technique is 
quite valuable for the follow- 
ing reasons. To find your own 
downlink signal at the 
beginning of a pass, you will 
always know where to expect 
your signal (i 1 kHz). Once 
you find your downlink 
signal, then you can QSY in 
increments — if you get lost, 
you can always return to 
your reference frequency plus 
Doppler and start over. 
Believe me, this happens, and 
this technique works. 

On OSCAR 6 and 7, Mode 
A, it is not unusual to 
actually be accessing the 
satellite, but, due to a num- 
ber of phenomena which are 
not clearly understood, you 
may not hear your own 
return signal. I have worked 
quite a bit of DX without 
hearfng my own signal. 

During my initial contact 
on OSCAR 7, Mode B, I was 
unable to hear my own signal 
because of downlink receiver 
desensing. Every time I keyed 
the transmitter 1 wiped out 
my receiver and, therefore, 



could not find my signal. I 
did not know whether I was 
getting into the satellite or 
not, but, by calling CQ 
repeatedly and tuning the 
satellite passband, 1 finally 
heard W2GN answering my 
CO (this is actually poor prac- 
tice) and now had a reference 
set of frequencies. 

The Art of DXing via Satellite 
For working DX alone, it 
is best to limit your antenna 
systems to low elevation 
angles. Concentrate as much 
energy (within reason) at the 
satellite so ihat as soon as it 
comes into range you have a 
workable signal. As has been 
mentioned previously, do 
not count on always hearing 
your signal. Sometimes it just 
isn't there, but others can 
hear you. To really work 
super DX via space is similar 
to 20 meters — you must use 
or try any tricks that seem 
reasonable. A technique for 
working a specified area is to 
use a high gain antenna(5) 
positioned at the midpoint of 
the satellite's ground track. 
This is a technique that was 



used to work KH6 from this 
area. The same technique 
could be used to attempt to 
work a UA9. 

At some frequencies (28 
MHz and above), another 
interesting phenomena can 
occur — signal ducting. This is 
best described by example. 

I have heard OSCAR 6 
when it was over Eastern 
Russia heading for the North 
Pole with excellent signals. 
This particular pass was quite 
removed from my normal 
window. 

On several occasions, 
WA4J1D (Ft. Lauderdale, 
Florida) has had an excellent 
return signal from OSCAR 6 
when the satellite was out 
beyond KH6 traveling toward 
ZL. Actually he had acquisi- 
tion for a period of 7 minutes 
after his normal loss of signal 
(LOS) time. There was no 
one to work, so he called CQ. 
Finally he dropped out and 
the next signal he heard was 
ZLIWB calling CQ on his 
frequency. WA4JID uses .35 
Watts to a 1 element cross- 
polarized antenna. 

ZKlDX regularly hears 
OSCAR 6 when it is over the 
East Coast of the U.S. 

Based on these observa- 
tions, it appears highly pds-"- 
sible that one could QSO a 
ZL from Southern latitudes. 1 
believe with a kW, some 
antenna gain and good CW . 
operating, it would be possi- 
ble to really stretch the 
normal communication 
ranges. 

In this regard, I do not 
believe that OSCAR 7, Mode 
B, is as easily stretched. The 
received signals just seem to 
drop when predicted LOS 
occurs. I can state that the 
downlink received signals on 
IVIode B are much better than 
what one will hear on 28 
MHz. An example of this is 
hearing 0A8V with his 10 
Watt ERP with a beautiful 
signal. 

Equipment and Antennas 

The equipment required to 
work OSCAR 6 and 7A is 
some type of 2 meter trans- 
mitter and a 10 meter re- 
ceiver. A good preamplifier 



for 10 meters will help 
immensely. Almost anything 
will work as the transmitter 
as long as the particular 
operator is satisfied with its 
performance. Here are several 
ideas for equipment that will 
work; 

1. An FM transmitter with 
provisions for keying installed 
and control of normal T/R 
relay (you do not want the 
relay to follow your keying 
or you will soon need to 
replace the relay). Note". Do 
not use FM for communica- 
tions via the satellites. 

2. A GE/Motorola FM trans- 
mit (TX) strip adapted for 
CW. 

3. VHF Engineering TX-1 50 
strip. 

4. Homernade/commercia! 
transverter and amplifier. 

5. Two meter CW/SSB trans- 
ceiver and amplifier. 

For OSCAR 7, iVIode B, 
the equipment required is 
somewhat more difficult to 
obtain. For the downlink, a 
reasonable 2 meter converter 
for an HF receiver will do 
quite well as will almost any 
of the present 4.nultimode 2 
meter transceivers. 

The uplink transmitter 
availability is somewhat 
limited. Several ideas for 
equipment include; 

1. GE/Motoro!a 450 FM 
strip convertecj fof'CW. 

2. Tripler for a 2 meter 
transmitter. 

3. Homemade/commercial 
transverter and amplifier. 

4. Commercial 432 MHz 
CW/SSB transceiver. 

5. GE/Motorola FM strip 
converted to be a high 
mixer/amplifier (SSB/CW). 

Further information on 
equipment requirements is 
given in the reference section 
at the end of this article. 

With respect to antennas, 
almost anything will work to 
some degree or another, but 
remember that the satellite 
requires a minimum ERP and 
the antenna for most low 
power transmitters is quite 
important. There are several 
general rules concerning good 
satellite antenna practice. 

Antennas do not need to 
be particularly high. For 



74 



DXing, what is important is 
tliat they be liigh enough to 
be in the clear. 

The antenna feedline loss 
becomes an ever increasing 
factor in VHF/UHF satellite 
operations. As the antenna 
heiglit is raised, so is the 
aiTi un t of fee d I i ne, 
preferably coax. At 
VHF/UHF RG-8 is ok, but, 
for example, at 146 MHz, 
100 feet of RG-8 will have a 
loss of 5 dB (including 
connectors). This 3 dB loss 
reduces the ERP to half of 
what there would have been 
if the feedline were lossless. 
At 432 MHz, 100 feet of 
RG-8 has 5 dB of loss. 

For 28 MHz, it is best to 
use two antennas, a beam 
pointed at the satellite (which 
need not be elevated), and a 
vertica! (1 use a vertical 
dipole). As the downlink 
signal fades, 1 switch from 
one to the other and vice 
versa. 

For 146 MHz, 1 prefer 
linear polarization. For DX, 1 
use vertica! polarization, and 
for the remainder I use hori- 
zontal. Circular polarization 
works quite well, but 1 don't 
like it on the horizon due to 
losing half my ERP in the 
opposite polarization. Cir- 
cular will have less fading, but 
for DXing the fading is 
mirtimal and can be toierated. 

For 432 MHz, the antenna 
situation becomes a little 
sticky — the size of the an- 
tenna is small but the chance 
for error in home built anten- 
nas is much greater. I recom- 
mend using standard proven 



antennas. Beware: Some 
antennas on 432 simply do 
not have the gain that is 
advertised. Basically a 6 to 16 
element yagi will be ade- 
quate. But, remember, the 
larger the antenna, the 
sharper the beamwidth, thus 
requiring accurate pointing. 
Conversely, as the antenna 
size is reduced, so is its gain, 
and thereby the ERP. 

in summary, a balance or 
compromise must be achieved 
in transmitter power, feed- 
line and antenna size versus 
pointing problems to obtain 
the performance that is 
desired. 

Various Amateurs' DX 
Accomplishments 

First of all, 1 am sure that 
there are sufficient unique 
DX accomplishments by a 
number of individuals that we 
could go on for some time. 
To mention a few — when a 
new country comes on via 
satellite, you can bet that 
W2BXA will be in there as if 
it were a "new one" for him 
for the DXCC Honor Roll. 
W8DX, W1NU, KIHTV, 
W1FTX, VE3SAT and a 
number of the Northern 
Jersey DX club members have 
worked over 50 plus coun- 
tries. Many have worked 5 
continents from the US. Asia 
is the most difficult. 

Conclusion 

Many amateurs, who have 
for years chased DX on the 
HF bands, have recently 
started working DX on the 
satellites and found it to be 




W3TMZ with his OSCAR array. 



every bit as challenging. Per- 
haps you too would like to 
join many of the HF DXers 
on OSCAR 6 and 7? If so, it 
is hoped that many of the 
ideas in this article wilt help 
you along to your fifty states 
via satellite or maybe even 
fifty countries. ■ 

References 

y.ARRL VHF Handbook. 3rd 
edition, p. 197, "Turnstile Anien- 
na," p. 133, "Two-meter Trans- 
vertsr." 

2. ARRL Radio Amateur's Hand- 
book, 1976, p. 108, "Tuvo-meter 
Transverter," p. 474, "Space 



Communications." 

3. Ham Radio, December, 1972, 
p. 6, "Signal Polarization," June, 
1974, p. 36, "Two-meter 
Preamp;" March, 1975, p. 34, 
"Az-El Antenna Mount," Julv, 

•197B, p. 5S, "432 MHz Oscar 
Antenna," January, 1976, p. 46. 
"432-1 6LB Antenna," March, 
1976, p. 44, "VHFv'UHF Re- 
ceivers — How to Improve 

-Them," May, 1976, p. 54, 
"VHF/UHF Techniques," July, 
1976, p. 50, "VHF/UHF Tech- 
niques." 

4. QST, December, 1974, Satel- 
iite feature issue. 

5. QST, September, 1975, p. 15, 
"Method for Phasing Crossed 
Yagis for Circular Polarkation." 



•^oon^; ^"ii. r. ' *. K- V <-.: 



L * K. 




from page 48 

single person much more than "I". 

I have never referred to myself as 
"we" and I have discussed this with 
ham friends, who generally agree that 
"we" is used only by hams who have a 
Lindberg complex; they seem to try 



to create the impression that they 
never use it in this way, but the very 
next time I hear them on the air, they 
are referring la themselves as "we." 

All this is somewhat confusing to 
me and the purpose of this letter is to 
locate someone who can teli me why 
this is done, how it got started, and, if 



there is no logical reason for its use, 
why do hams continue to use it? 

Just as a paning shot, why don't 
hams on voice just laugh instead of 
saying "iii"? 

Keep the good worl< going, Wayne; 

you have a forty over nine magazine. 

Walter A. Deiter KH6AiMM 

KaiiuaHl 



SCIFI 



Several months ago I sent you a 
note which requested hams who read 
science fiction to write me. You 
printed it in the Ham Help column. 
For that I thank you very much, I 



received a number of repiies and have 
come up with some more information. 
! would appreciate it if you would 
print it as a foilow-up. 

72E0-7255 kHz have been desig- 
nated as calling frequencies for hams 
v,rho want to discuss science fiction. 
7250 will be used in the evenings, and 
14310 can be used on weekends day- 
time. This will not be a net or any 
type of directed operation; rather, tt 
will be simply a gathering frequency 
tor interested persons, Just get on and 
holler "CQSF!" 

For any other information, write 
me at the following address. 

Neil Preston WB0DQW 

7024 Bales Ave. 

Kansas City IMO 64132 



75 



OSCAR 
Frequency Relationships 



- - now, where is my downlink ? 



Robert H. Main VilZAW 
Bible Hill Rd. 
Hillsboro NH 03244 



Best for beginners . . . preferred by pro's! 

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9: 




V 



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all sure-handed . . . 
smooth operating 
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$6.95. 



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Fast, comfortable, easy . . . and fun! 

Model SSK-1 (shown) 

$23.95 

Model SSK-3 (has 
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Wtiether you're a "brass poundef" or a side swiper" 
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1614 - 130th Ave. N.E., Bellevue. WA 98005 ^4 





One of the most difficult 
things to get a handle 
on when you first start out 
on OSCAR is the relationship 
between uplink and downlink 



frequencies. Ever hear a signal 
on 29.440 MHz and wonder 
what frequency you should 
be transmitting on? You look 
for your hand calculator, 



UP DOWN 

14^j.900=..>7.450 
145.901=29.451 
145. ?0?-"'^. 4iJ2 



145, 
145. 
145, 
145 , 
145. 
145. 
145. 



904 -;:'?, 

905-2 9, 
9O0 :29. 
907'^=29. 
9 03.^^^29. 
909=29 . 



45.J 
454 



458 
459 



J,45.910==29-4c)O 
14 5.911 ■ '' 9 . ? 6 1 
14 5. 911: 2V.Aa-' 
145, 9 1,1-29. 46;i 
14S. 914=29.464 
1 .-^ D . 9 1 5 ^ '.Iv' ' 4 iS 5 
14 5.91l^ 29.4t6 
l^'j i'-- :./,' ^y.4A7 
14;. .91D- ....9. i?^.H 
145.919 



2 9 . A A 9 



14 5,920 ■^29.470 
145. 921 '-29. 471 
145^922-29.472 
1415. 92J-29, 473 
145.924=29.474 
145,925.-29.475 
145.92A-29. 476 
145. 92;' 29.477 
145,92.1^ "^9 > 47f3 
145.929^=29.47? 

145,930=^29.480 
145. 931 --^2 9. 431 



145.9:^2-29.482 
14 5,9 73 = 29,4R,-> 
145.934 = 29, ■■!94 
145.9i5^29.4f)5 
3 45 , 9 2 ^=-'29 , 4S.'; 
145,937==2?.4;!7 
14S< 93ii^29.42!:i 
145,939-2 9,489 

145, 940-.--2 9.4 90 
145. 941 .-2 9. 491 
145, 942-29 -4 72 
145.943=29, ■!92 
145- 944 =^29,494 
l';5-'-45=-29,49;,. 
145 , V ■i.:i = 2?, ■J.9'> 
] -' ;, , i.'-i .'-.= 29 > 'I'.'' .' 



J -2 
14' 



, 4 9 9 



145.9':0--29.5'J0 
145.951=29.501 
14G.952=.^29,502 
145*953=29.503 
14 5,954-2 9.504 
14S.955==29.505 
i<!5.95.1,-.29,506 
145. .95 7^^29.50/ 
145. 75G^29.:,'.^V, 
14 5.959-29.509 



1^5.950^^29. 
: 4V . 9... L^2..5 
145.'; 52^-29: 
145. 963=29. 
14 5.964^.2 9. 
145.9^5^=29. 



no 

i 



145,9/..4-29.516 
145,967-^2vV51? 
145.9 5^-29.518 
145.9o9:^29.519 

145. 970-29,520 
145 . 971:^29 . 531 
:|,4S;, 97 ■-29,522 
145, 97^=29.523 
1 45 < 974=29. 524 
145.975=^29.525 
145, 976=^^29, 526 
143.977=29.527 
145. 978-29. 52S 
145.979=29.329 

145.9EI0-.:29,530 
145.981 =^29.531 
145.9n2-2','.532 
. .145.9B.v-29.333 
145. 984. =29. 53 4 
145.935=29.535 
145,906-29,536 
145; 987 -.29. 537 
145, 988=29. 538 
145.9S9.= 29,539 

145.990-29.540 
145.991 -^29.541 
145.992=29.542 
145.99 < 29.543 
145.9^4-29.54 4 
5 45. '-9 5- ..'9. 545 
J 45.9'^'6 29.:,.},:, 
143.997 :-29, 54/ 
145,99i-!-2.;--.54!;! 
145. 999... 29. 549 



Fig. 1. OSCARS. 



76 



only to find that it is on your 
desk at worlc. So you have to 
tate pencil in hand and try to 
find some paper to figure 
things out. By the time all 
that has been accomplished, 
either the satellite has flown 
over, the station you were 
hearing is talking to someone 
else, or the station is out of 
range. 

Having had that experi- 
ence too many times, i 
decided it was time to have 
some printouts at my finger- 
tips, or on the wall next to 
my operatiiig location. So, 
with the help of a computer, 



UP 

432. :l. 
432. t 
43'"^ '! 



43^: 4 A.2V 
432,130 

432,132 

432.134 

4 3 2 i J, 3 7 



DOWN 

OUTF-'UT FC 



145, 

145. 
145 V 
145. 
1 ji '■■: . 



139 = 



4 >:!■ .:; . "i. 4 U 
"f ij i. * 1 ■,■•■ J. 
4 3 2 , 1 4 2 
432. 143 
4 32, 144 

432. 145 

432 . 146 
432.147 
432,148 
432,149 
432.150 
432,151 
432.152 
432.153 
432,154 
432.155 
432. 156 
432.157 
432.153 

^^ t: 7, ^ k; <:;• 

432, 160 
432,161 
432, 162 
432,163 
432.164 
432,165 
432.166 
432.167 
4 3 2 .168 
432.169 
432, 170 
432.171 
432,172 
432 , 173 
432.174 



145.962 
145. '7 6 '^ 
1 4 5 . 9 6 
145,959 
145,953 
145,957 
145,956 
145,955 
145,954 
145.933 
145,952 
145,951 
145.950 
145 s 949 
14S.94S 
145.947 
145.946 
145.94 5 
145.944 
145.943 
145.942 
145,941 
145.940 
145. 939 
145.938 
145.937 
145.936 
145,935 
145,934 
145,933 
145,932 
145.931 
145,930 
145.929 
145 . 928 
145,927 
145.926 
145,925 



Fig. 2. OSCAR 7, mode A. 

the accompanying tables have 
been developed. As you can 
see, OSCAR 7 users (mode B) 
would really have a calcu- 
lating problem tripling up 
from 2m. It's a simple matter 
to use the desired listening 
frequency and follow across 
the chart to find the desired 
transmitting frequency. We 
carried this out to five places 
so that anyone rockbound 
could order crystals easily. 
Also, the telemetry fix on 
board OSCAR 7 has been 
putting out a good sigriai and 
is an excellent way of 



UP 



J 
1 

) 1 

1 



1 \ i 



DOWN 

I I 
i 

> 1 



5 X 
) 

s 
4 1 1 



4 
Jl 

4* 
1 4 
1 ' 



■! K 


' ) 


1J 


\ 


1 " 


\ 


I i ' 


IT C 


1 1 




1 1 ) 


c- 


1 1 


E 


1 1 


J 


]a 1 


' 


1 \ 


c 


J J 1 


« 


1 '' 




1 


K ^ 


3 n 


1- 



UP 


DOWN 


145 


.882 = 


-29 


432 


145.850- 


= 29 


400 


145 


.88 3 = 


29 


4 33 


145.i;;51-- 


=29 


401 


145 


.8S4 = 


29 


4 34 


145,852- 


^29 


402 


145 


,885 = 


29 


435 


145.853- 


=29 


403 


145 


.886^ 


29 


436 


145, 854=^ 


-29 


40 4 


145 


.387--- 


29 


4 37 


145.855=- 


29 


405 


145 


. 888 = 


2 9 


4 38 


145.856-= 


= 29 


40 6 


145 


. 889=. 


2 9 


439 


145.857= 


= 29 


40 7 










145.85!;!=. 


2 9 


40 S 


145 


.890=- 


29 


440 


145,859= 


29 


40 9 


145 


.891 = 


2 9 


441 








145 


. 892-= 


29 


4 42 


143,860= 


= 29 


410 


145 


,893- 


2 9 


443 


145.861- 


= 29 


411 


145 


. 894.- 


2 9 


444 


145.862= 


^2 9 


412 


145 


. 895=. 


2 9 


445 


145.f)63 = 


= 29 


4 1 3 


145 


.89 6= 


29 


446 


145.864= 


= 2 9 


414 


145 


897 = 


29 


44 7 


145,865- 


■-29 


4 1 5 


145 


39!:= 


2^ 


44 3 


145.866 


:2 9 


4 1 6 


1 4 5 


89 9 = 


29 


44 9 


145.367^ 


=2 9 


4 1 7 










145,86 8- 


= 2 9 


4 1 a 


145 


.900 = 


= 29 


.450 


145,869= 


= 29 


419 


145 


.901 = 


29 


451 



145.870=29.420 
145.871==29.421 
145.872=^29.422 
145.373=29.423 
145.874=29,424 
145.875=29,4 25 
145,876=29,426 
145.877=29.427 
145,878==:29.428 
145.879=29,429 

145.830=29.430 
145.881-29.431 



145.902=29.452 
14S.9-03==29,453 
145, 904== 29. 454 
145.905==29. 455 
14 5. 906== 29. 456 



145.916=29.466 
145.917=29.467 
145.918==29.463 
145.919=^29.469 

145.920=29.470 
145,921=29.471 
145.922==29.472 
145.923=29.473 
145,924=29.474 
145.925=29,475 
145.926=29.476 
145.92?==29.477 
145.928=29.478 
145,929:=29.479 

145.930=-29.480 
145.931=29.481 
145,932=29.482 
145.933=29.483 
145.934=29.434 
145.935=29,485 
145.936=29.486 
145.937=29.487 
145.938=29.4 88 
145.939=^29.489 



145 
145 
145 


.90 7 = 
. 908^ 
. 909= 


=29.457 
^29,453 
-29,459 


145 
145 
145 
145 


.940 = 
.941 = 
.9 42 = 
. 943- 


= 29 
= 29 
^29 
^29 


490 
491 
4 92 

49 3 


145 


.910 = 


=29.460 


145 


.9 44- 


^29 


4 94 


145 


.911- 


^29.461 


1 4 5 


.945^ 


■ 2 9 


495 


145 


.912^ 


^29.^462 


1 4 5 


.946. 


■ 2 9 


4 96 


145 


.913- 


29.463 


145 


.947^ 


■ ':^ t > 


4 9 ? 


145 


.9J4 = 


^29.464 


145 


,94 8^ 


^2 9 


493 


145 


.915- 


^29.465 


145 


,94 9: 


. - 1 I'l 


499 



V 



D 



B ^ 




We have a portable direction finder tRar REALLY works— on 
AM, FM, pulsed signals and random noise! Unique left-right 
DF allows you to take accurate bearings even on short bursts, 
with no 180 ambiguity. Its 3 dB antenna gain and .06 uV 
typical DF sensitivity allow this crystal-controlled unit to hear 
and positively track a weak signal at very long ranges— while 
built-in RF gain control with 120 dB range permits DF to 
within a few feet of tfie transmitter. 

The DF is battery-powered, can be used with accessory 
antennas, and is 1 2/24V for use in vehicles or aircraft. This is a 
factory-built, guaranteed unit— not a kit. It has been successful 
in locating malicious interference, as well as hidden trans- 
mitters in "T-hunts," ELTs, and noise sources in RFI 
situations. 

Prices start at under $175. Write or call for information on our 
complete line of portable, airborne, vehicle, and fixed DF 



systems. 

5546 Cathedral Oaks Rd., 

Amateur Dept. 

Santa Barbara, CA 93111 



Fig. 3. OSCAR 7, mode B. Telemetry beacon: 432.100. 



L-TRONICS 



L10 



805-967-4859 



77 



IN 



1,45: 

1 !■;;. 



OUT 



IN 



1 .:. 



3 •■■:: 



1 4:. . 8d 



"9 


-1 


^ /. ^ 


'/ ■-'•■' 


29 


-X)! 


■. -' -1 


■-' , , 


29 


40 2 


.■ -; ;^: 


v<j1 


29 


4 0ri 


1 4 ■-• 


''■<:-A 


2? 


4';<i 


\ ■:■■-■ 


■V05- 


29 


-ll.'lj 


1 ' '" 


. 9~3 


29 


-; ■', n 


1 4 '-■ 


.- :''•- ' 


29 


-10/ 


14S 


.:;0>- 


2 9 


.a,;>;"; 


1 4 ^;; 




2 7 


■5 09 


:l. 4 5 


910 


29 


410 


145 


■91 1, 


2? 


411 


143 


, 9 1 ■ ' 


29 


-'• 1 2 


14:. 


. ';' J. 3 


2C' 


■', : ', 


1 .* ^' 


■"--■■ j 


T V 


^ i^ 


' 4? 


■-. 1 - , 


29 


•i 1 1.. 


1 ■■; _: 


. V ' ■_. 


^>:i 


1 !. .'j 


143 


■ *1 ".' 


29 


-1 ' -^ 


■ 4 3 


.^« c- 


■-■' v' 


■! i 3 


1. 4 3 




29 


i 1 '.■> 


1:3 


n ■-' ■^ 


29 


4 20 


143 




29 


4 21 


1 43 


, 92 2 


2 9 


422 


143 




2 9 


42:ri 


145 


'-:■ ■:■ ;^ 


29 


424 


1 4 3 


. '-3:3 


29 


4 2:j 


1 4 3 


, 92.'. 


29 


42(S 


J, 4 -"■ 


■ ';' : : / 


29 


-127 


1 :3 




29 


4 2;.! 


1 -^3 


. ■-■2^"' 


29 


429 


1 -1 5 


. 930 


29 


4 JO 


1 '■ " 


.971 


29 


4;!1 


■; 45 


■-. '^■*'l 


29 


4:i2 


1 4 3 


-. '^''^- '. 


2? 


■t:;:^ 


^ ', ^; 


.73-; 


2 9 


4i4 


145 


* V Z Z 


29 


■!3;5 


1 4 3 


. -'J-'/' 


29 


436 


145 




29 


4 37 


j 43 


.93e 


29 


4 3.':! 


1 4 ^,. 


^;> 7; 


29 


439 


143 


H t:-,;,j 


29 


440 


1 43 


.941 


29 


44 i 






2 > 


4 ", ;.' 


-t -. •—, 


, ;-'-13 


2 9 


4 4 3 


143 


?-:".* 




,1 ,1 .1 


143 


- 9 -';■' 


:■■> 


4-K.. 
4 ■; .■> 


1 -;3 
1-13 


^ .3 J , 


29 . 


4 •, 7 


J 43 


.. \^ ^' . ": 


2^ . 


4 4a 


143 


.. 9,;V"> 


2 9 -, 


4 4 9 


1 4 3 


. "30 


29. 


4 'SO 


143 


.931 



OUT 



2?, !S;3 



, 4o/ 



29, 4? 



IN 

j^2-: -...0 

1 :3. .■■;>i 

-43: 202 
143 • -"03 
1 ■■■ 3 , r '" i; 
14" "'23 



OUT 



IN 

?Ci''i .143. .'"M 



29.459 143.9 03 

29.. .160 145, 909 

29,461 143, -'10 

2'"' . ^32 143, "1 I. 

29, .343 143., 2j;: 

29 . 4.^ ■' "! 4?3 9 ' 3 

2'9 . 4.;. "' 143 . ■/ ' ': 

2^.1^^-v 143, ^-13 



i43,91c. 



14' 



29 


47 4 


143 


, 923 


;;■ 


4 33 


143 


.921 


0'7' 


A "■'.-, 


1 .-■; j: 


.-■■-.'■; 


■-> c; 


4 9 4' 


J /.=;; 


:■..-', 


^. :-. 


" ,. "'. 


. -. 




— ■' 


. ■ - 


-. ■ -' 




:^y 


'!?■■-;■ 


143 


.- 0.0 


j-'9 


483 


; - ^ 


■"1-5' 


29 


AHi 


1.C3 


■^■30 


29 


/7 J^ "-. 


J. - ■ 


-■31 


'j^< 


■■'■ ■ ; ''■ 


■f :■'. ^"1 


. 4 2.,.; 


29 


■iai; 


1,ig 


.,..; , 


29 


4. 9 A 


14 3 


. 91:3 


29 


,4S7 


145 


T' ■ ; -■ 


29 


4S.9 


145 


, V 57 




4£V 


143 


',■ ' ^■'■ '--ii 


2? 


-1VC 


145 


>'-3 '.'' 


^9 


■T"'-l 


143 


■ ._ - 


29 


-??2' 


! 4,v 


■-,' :: 1 


■■■jO 


4^-3 




. -,1 2 


2 -■ 


4 V 1 


.; ■■■;"' 


■■■'■:: 


■?^' 


4?;; 


1 i;J" 


" ■■ 1 


2'^' 


496 


143 


■ ■: :/ 


2'/ 


4 ';' 7 


1 ..'i"i' 




jV V 


4 9 9 


- J =^ 


r: .^ 7 


29 


-199 


14 3 


■- i^ \-\ 


2 ';■' 


300 


1 ^v 3 


r; ,-i 'J,-- 


29 


301 


143 


/^HO 



.rt-4^ ^^.V 



-, ■' Z- 


; ""■■■ 


1 -■; 3 


■■ .4 


4:":" 




1 ■:3 


V" "J- 


,1 -._ ' ; 


'. • 


■i _i L , 


■'. A 


4 33 


T ■ 2 


1 .1 .-", 




,) -/ ^,^ 


:: ■■■2 


143 


'■■"19 


4 33 


:l. <:■•■ J, 


1 -.1 \'^ 


962 


4 33 


, ) '"■■■3 


143 


9 ;:■ ;: 


4 ■;■: <::, 


> [.■■■' 


:i 4 3 


.:■ •. -. 


4 3'-! 


, 3 ■■I 


1 ..; 1; 


■■33 


.'.".* .■; 




143 




..3-:'-. 


! ■ ■ • 


143 


■?■■' '..- 


433 


.133 


14 3 


■■ 1' .' 



43: 

43:v 
43f 



43' 
4.3:: 

435 



43' 



. 1 63' 



14 = 



1 4 3 3? . ■ .. 

143. '■■3'' 3 
■L 4 3 , •■:! 7 ■'. 
143,923 
14'^. ,■'■ 3 
1 <; ■-, , ■;. 7 ^7 

1 ■■3 V/E? 
14,'>,?7? 
143, f 00- 
14 3.93: 
14'-;,93J^ 
14 3 T;: 



I-':'- 



1 ■! 3 , ■ 



i3q.l^ ^■■3/-^-'.'3 

ij>5. 1 52 1 •;'-.. - '■'5 + 

-■"?5.15j-~- 1 4*3 ( -775 

'^■■': .122 1 .i'^- V'^^'s 



143, ■•■'2^ 

■I43.0v;0 

14(4oOC I 



OUT 




435. 


1^4 3 


■1 .^S 


14S 


■11':^ 


■; .-^ '7 


4 j3 


143 


■^:?5 


1-13 


4:«!3 


f «4 



■.!3; 
,1 "i; ' 



J 41 



, 1 ^3 



4:.'^ . 

4 3/j. 



131 



433, 12' 



43r''i 


] 26 


^1 "■:'■, 


1 }A 

' 23 




iii 


435 . 


JLJO 


ASli 


li? 


4T". 


I.i-B 


■53r. 


1 17 


43:; 


1 :? '^^ 
1 l IJ 
:i. 1 4 

;[ 1. 3 


4j!J 


.:. ]. 2 
;!. !l. 1 
1 1 
109 


4j3 


lOB 


-135 


107 


4^S 


iO,i 


<*7.n 


JO? 



53, 102 



Fig. 4. OSCAR D, mode A. Telemetry: 29.400. 



Fig. 5. OSCAR D, mode J. Telemetry: 435.095. 



checking your receiver. 

By the w;iy, don't forget 
the Doppler effect which 



causes the saieihte Lo gr;id- from your location. But 
ually shift in fiequency as the Doppler effect or not, the 
bird moves toward or away relationship between the 



various uplink and downlink 
frcqttencies will remain 
consistent. ■ 



I Bearcafc'/// Scanner 

I 

I 

I 

I 

I 

I 

I 

I 

I 

I 

L 




$289. 

The Bearcal 210 super synlhesized receiver 
scans and searches 32-50, 1<I6-174 & 
416-512 MM^ without expensive t;rvslaJs. 
Order now on our 24 hour lell-free credit 
card order ine iiOD-521-4ii4 In Michigan 
and outside [he U S tail 31 3-994-4441. Add 
S5 M tor sMrpping .- US. 3^ 59 00 lo' 3:' 
UPS 10 'Aiesi iDcST Chd.-ge -rar:!?. ir r-.-.-z^.ey 
orders nnry i^c-einn ercers invh^- Fo' 
aocrt.i;.'!^! rucrma^^en. ..^.riie Cuh^rr.uri- 
ca-.ic-,s £-e;:'Qr-.|C'a P.O Box 'ikQ Obc:. 



A.- 1 1 A-'^'^rj-r. 






3106 



G 



COMMUNICATIONS ELECTRONICS 
P.O. BOX 1002 DEPT. 73-11 
ANN ARBOR, MICHIGAN 48106 



CDAKIT 

Now stocks AMPHENOLI 



P.O. Box 101-A - Dumont, N. J. 07628 

C21 



C5 



78 



PREAMPS 



HIGH GAIN •LOW NOISE 

30 dB power gain, 2.5-3.0 
dB N.F. at 150 MHz, 2 
stage, R.F. protected, 
dual-gate MOSFETS. Man- 
ual gain contfol and pro- 
vision for AGC. 4-3/S" X 
1-7/8" X 1-3/8" aluminum case with power 
switch and your choice of BNC or RCA 
receptacles. Available factory tunad to the 
frequency of your choice from 5 MH^ to 350 
MHz with approximately 3% bandwidth. Up 
to 10% B.W, available on special order. 
Requires 12 VDC @> 10 mA. 

Model 201 price (5-200 MHz) $29.95 

201-350 MHz S34.95 




CONVERTERS 



2 METERS 

This converter has a 
miniTTium of 20 dB gain 
and a noise figure of 
2.S-3.0 dB which 
assures you of a sensi- 
tivity of .1 microvolt or 
better. The circuit uses 

a dual-gate MOSFET R.F. stage and a dual- 
gate MOSFET mixer (thereby giving you a 
minimum of cross-modulation products), 6 
tuned circuits, a bipolar oscillator and .005% 
crystal. Covers 144-146 MHz at 28-30 MHz 
output with one crystal included and 146.143 
MH2 at 2S-30 MHz with an extra crystal 
(avaiiable for $6.00 more). The glass epoxy 
circuit board is enclosed in a 16 gauge 
aluminum case measuring 3-1/2" x 2-1/4" x 
1-1/4" with your choice of either B(\!C or 
RCA receptacles. AJso included is a power 
and antenna switch. Requires 12 VDC @ 15 
mA. The converter is also avaiiabJe at other 
input and output frequencies. Call us for 
prices. PRICE: Model C-144-A available from 
stock at $39.95 with one crystal. Additional 
crystal $6.00 extra. 

HP & VHP 
40 dB GAIN 2.5-3.0 
N.F. @ 150 MHz 
2 RF stages with tran- 
sient protected dual- 
gate MOSFETS give 
this converter the high 
gain and low noise you 
need far receiving very 
weak signals. The mixer 
stage is also a dual-gate 
WIOSF ET as it greatly reduces spurious mixing 





o ■ 



SYNTHESrZERS 



FOR ALL TRANSCEIVERS 

The STR series syn- 
thesizers are avaflable 
for any transceiver 
operating from 20 MHz 
to 475 MH^ that uses 
crystals in the 5 to 85 
MHz range. It has 3 

thumbwheel dial calibrated for your operating 
frequency plus a selectable transmit offset of 
plus or minus 600 kHz, plus or minus 1 JVIHz, 
and 2 spare offsets that you can add later. 
Frequency accuracy is .0005% and spurious 
outputs are 60 to 70 dB down. To process 
your order we must have the crystal formula 
of your transmit and receive crystals. If your 
transceiver uses T crystal for both trans- 
nnittmg and receiving (Hke the iVtotorola 
Metrum II), you can use our receive synthe- 
siser described to the right- iVlaximum tuning 
fange per synthesizer is 10 MHz above 100 
MHz and proportionally less at lower frequen- 
cies. Dial increments are in 1 kHz steps from 
5 to 30 MHz and 5 kHz steps above. 
ModeJ STR synthesl:zer price 

5-1 50 MHz $259.95 

151-475 JV1H2 $279.95 



yanauard 
§aEs 



VI 



EXTRA LOW NOISE 

Excellent for weather satel- 
lite reception and recom- 
mended by Dr. Ralph E. 
Taggart in his Weather 
Satellite Handbook. Less 
than 2 dB noise and 
approximately 17 dB gain. Uses a low no^se 
J-FET in a common source neutralized cir- 
cuit. Available factory tuned to your choice 
of frequency from 135 MHz to 250 MHz. 
Bandwidth approximately 4 MHz. Supplied in 
a 2-1/4" X 1-1/8" X 1-3/S" die-cast aluminum 
weather-proof case vuith a filter for powering 
it through the antenna. Requires 12 VDC @ 5 
mA. Choice of VHF, type "N", or BNC 
receptacles. 
Model 102W PRICE $36-95 



products — some by as much as 100 dB over 
that obtained with bipolar mixers. A bipolar 
osciHator using 3rd or 5th overtone plug-in 
crystals is followed by a harmonic bandpass 
filter, and where necessary an additional 
amplifier is used to assure the correct amount 
of drive to the mixer. Available in your choice 
of input frequencies from 5-350 MHz and 
with any output you choose within this range. 
The usable bandwidth is approximately 3% of 
the input frequency with a maximum of 4 
MHz. Wider band widths are available on 
special order. Although any frequency com- 
bination is possible (including converting up) 
best resuits are obtained if you choose an 
output frequency not more than 1/3 nor less 
than 1/20 of the input frequency. Enclosed In 
a 4-3/8" X 3" x 1-1/4" aluminum case with 
power and antenna transfer switch and your 
choice of BNC or RCA receptacles. Requires 
12 VDC @ 25 mA. 
Model 407A price: 

5-200 MH^ $54.95 

201 -350 MHz $59,95 

Prices include .005% crystal. Additional 
crystals $8.95 ea. 



UHF 

20dBIVIIN. GAIN 

3 TO 5 dB MAX N.F. 

This model is similar in 

appearance to our 

Model 407A but uses 2 

low noise J- PETS in 

our specially designed 

RF stage which is tuned 

with h igh-Q miniature 

trimmers. The mixer ts a special dual-gate 

MOSFET made by RCA to meet our require- 




196-23 Jamaica Ave. 
Mollis NY 11423 
(212)468-2720 






FOR VHF RECEIVERS 

This synthesizer has 
SOOO channels and can 
tune a continuous 40 
MHz segment of your 
choice from 110-180 
MHz in 5 kHz steps. 
This will satisfy most of 

your requirements in the VHF range and can 
save you hundreds of doiJars m crystals plus a 
lot of time. Stock units are progirammed for 
your receivers with the crystal formula Fc ^ 
Fs -10-7 divided by 3 but we can program it 
to almost any other IF at no additional cost 
at the time of your order. It is supplied with 
an interface for plugging in to your existing 
crystal socket. Requires 12 VDC @ i/2 amp 
which is easily obtainable from a low cost 
power suppiy. The synthesizer has 4 voltage 
regulators therefore the power supply need 
not be regulated. Phase noise is not detectable 
as the VCD is coarse tuned by a DAC thereby 
easing the requirements of the phase-locked 
loop not affected by vibrations encountered 
in mobile use. Enclosed in an 8" x 3-7/S" x 
1-1/2" aluminum case and supplied with a 
combination tiit stand/mobile mounting 
bracket. 
Price: Modet SR-140D-05 $179.95 



NOTE: We can make any synthesizer from 
audio to 475 MHz. Call us for prices. 



UHF 
3 TO 5 dB MAX. N.F. 
20 dB MIN. POWER GAIN 
Uses 2 of Tl's low noise 
J-FETS in our special 
circuit board design which 
gives a minimum of 20 dB 
power gain at 450 MH2. 
Stability is such that you 
can have mismatched loads without it oscil- 
lating and you can retune (using the capped 
openings in the case) over a 15-20 MHz range 
simply by peaking the maximum signal. Avail- 
able tuned to the frequency of your choice 
between 300-550 MHz. 4-3/S" x 1-7/3" x 
1-3/S" aluminum case with power switch and 
your choice of BNC or RCA receptacles. 
Requires 12 VDC @ 10 mA. 
Model 202 price $34.95 



mtns. The oscillator uses 5th overtone crystals 
to reduce spurious responses and make possi- 
ble fewer multipliers in the oscillator chain 
which uses 1200 MHs bipolars for maximum 
efficiency, Available with your choice of 
input frequencies from 300-550 MHz and 
output frequencies from 14-220 MHz. Usable 
bandwidth is about 1 % of the input frequency 
but can be easily retuned to cover more. 
Requires 1 2 VDC @ 30 mA- 

Model 408 price $59.95 

.005% crystal included 




In your choice of 



VHF RECEIVER 



1 1 crystal controlied 
channels. Available in 
your choice of frequen- 
cies from 135-250 MHz 
in any one segment 
from 1-4 MHz wide. 
t.F.' bandwidth (chan- 
nel selectivity) available ... ,__ _. 

±7.5 kHz or ±1 5 kHz. 9-pole quartz filter and 
a 4'pole ceramic filter gives more than 80 dB 
rejection at 2X channel haired width. Phase 
locked loop detector. Frequency trimmers for 
each crystal- .2 to .3 microvolt for 20 dB 
quieting. Dual-gate MOSFETS and integrated 
circuits. Self-contained speaker and external 
speaker jack. Mobile mount and tilt stand. 
Aluminum. case, 6" x 7" x 1-3/8". 
Model FMR 260-PL price; 

135-180 MHz $149.95 

1S1-250 MHz $159.95 

Price includes one .001% crystal. Additional 
crystals $8.95 ea. This receiveK^Ts recom- 
mended in Or, Taggart's ' Weather Satellite 
Handbook.^ . ■ 



HOW TO ORDER: AIJ items on this page are 
available only from Vanguard Labs. For re- 
ceivers and converters state model, input and 
output frequencies, and bandwidth where 
applicable. For the fatest service call (212) 
468-2720 between & AM and 4 PM Monday 
through Friday, except holidays. Your order 
can be shipped COD by Air Parcel Post. 
BY MAIL: Send your order to Vanguard 
Labs, 196-23 Jamaica Avenue, HoUis, NY 
11423 ahd Include remittance by postal 
money order, cashiers check or certified 
check. Personal checks are also accepted, but 
banks now require 3 weeks for checks to 
clear, therefore this will delay you r order. 
Include sales tax if you reside in New York 
State. 

PURCHASE ORDERS: We accept purchase 
orders from US and Canadian government 
agencies^ universities, and AAA rated corpora- 
tions. Our terms are Net 30 days. 
FOREIGN ORDERS: Must remit payment in 
full in US funds plus postage and insurance 
fees. If complicated customs forms are re- 
quired, please forward your order to an 
irriport-export agent. 

SHlPPrNG: We ship ail our merchandise by 
insured parce] post or air mall. Special de- 
livery Is also available. Prices include shipping 
by regular parcel post If you remit with your 
order. For air mail shipping add $1 .00. 
Postage wiil be added on all CODs, purchase 
orders, and foreign orders. 



79 



J. W. Maniette VE7BGX 
#302-33400 Bourquin Place 
Abbotsford, British Columbia 
Canada V2S 5G3 



Calculate 
OSCAR Orbits 

-- with your HP-25 calculator 



Last year I developed an 
interest ir. OSCAR activ- 
ity after having read a back 
issue of 73 that was entirely 
devoted to this subject. When 
I sat down to work out the 
orbital times to look for 06 



and 07 in my area, 1 decided 
very quickly there had to be a 
better way. The calculation 
of orbit #5, for example, on 
any given day can be a time- 
consuming effort at best, and, 
if you want the most likely 



HP-25 Program Form 



Progr.TTimer J. JiMSl^'IIE— 



H5TRU;.-OMS 



Keij in p^'Cai'jr. 






LtnJ Ergc^anz^zi— 






]L^DC 



Zi 



L ^1 II II 1 



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_£5_25£ 1 ■'^TO 



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80 



times for communication via 
this mode on a daily basis 
throughout the month, these 
calculations could be a down- 
right nuisance unless you 
have access to a complete list 
of tables for this purpose. 

Since my HP-2S was sit- 
ting idle and I was still trying 



to justify its purchase price, I 
decided that it was about 
time it should start doing 
more than calculating debits 
from my savings account. 

This program is not very 
complicated in the sense that 
it doesn't work out any heavy 
math problems, but it does 
do the job of working out the 
orbits of cither 06 or 07 
between the times listed each 
month in 73. The program 
will update the orbital num- 
ber, the equatorial crossing 
and time of crossing for each 
successive pass from the first 
pass listed for each day. If 
you wish, subtracting the 
number of hoLirs you are 
from GMT on the first entry 
will result in a local time 
readout for the equatorial 
crossing. 

An example is probably 
worth a thousand words, so 
let's take the case of orbit 
#19264 on January 1, 1977, 
for OSCAR 6. (See Table I.) 
My QTH is eight hoors from 
GMT; therefore, subtracting 8 
hours from 0124:02 and 
adding 24, we arrive at 
1724:02 local time. This, of 
course, is the day before or 
5:24 pm on December 31. 



Tiiic 






HP-25 


Program Form 

k..n., 




^iv idJ- V-' Ppr^V -cdt fjier.: jj _'^y^_i . U .■ 'f, ■ i^z t-l'. ■■^ 






u 


SPL/lY 


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nmiMCWTs 


KEGISrERS 




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5.1 JUJjU'^t* ^J 










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j[ 







































Orbit # 
19264 



Date 

1 



Time (GMT) 
1:24:02 



Eq. Crossing W 
79.5 



Data 



Table 7. 



Key in the program infor- 
mation using tine HP progrann 
forms. When the program is 
run, the pause will give the 
pass number, and the first 
stop will give the time. Press- 
ing the R/S key will then give 
the equatorial crossing longi- 
tude for this orbit. The draw- 
back to this program is that 
you have to go through each 



pass to reach the one you 
want, but, unfortunately, i 
haven't figured out how to 
get an extra register and 30 
more program steps into the 
calculator in order to elimi- 
nate this problem, so I guess 
this will have to do until 1 can 
get my Micro P operational. 
(See Table 2.) 

Hopefully this article will 



Orbit # 


Local Time 


19264 


1724:02 


19265 


1919:01 


19266 


2114:00 


19267 


2308:59 


19268 


0103:58 


19269 


0258:57 



Equatorial Crossing { Long.) 

79.5 

108.25 

137 

1 65.75 

194.5 

223.25 



Table 2. 



encourage other members of and other areas of our hobby 



the ham community with ac- 
cess to one of these calcula- 
tors to sit down and work out 
additional programs for this 



f this is the case, I will be 

looking forward to seeing 

these programs in future 
issues of 73. ■ 



Corrections 



Texas legal beagles and scanner 
manners have indicted us for stating 
that the "Big Sust In Amarillo" (Oct., 
p. 154) took place on July 7th. We 
throw ourselves on the mercy of the 
readership, and readily admit that the 
date was, indeed, July 6th. No more 
letters, please. 

John C. Burnett 
Managing Editor 

Our apologies to Harry Matthews 
K2A0U, for inadvertently omitting 
the documentation for his Main Buf- 
fer System ("Digital Group RTTY 
Micro," Sept., p. 9S). Here it is. 

John C. Burnett 
Wlanaging Editor 



1 think I've found an error on page 
47 of your August issue. The diagram 
for the Zeppy Vertical shows the 
braid of the coax attached to the 
radiator and the center conductor to 
the matching stub. These connections 
should be reversed. As written, the 
antenna was inferior to a /4 wave 
whip, Reversed, it improved on the % 
wave by several S-units. Keep up the 
good magazine. 

Tim Knauer WD9AMY 
Peoria IL 

In addition to my new call and 
address, please note several minor 
changes to "Synthesize Yourself!" 
(Oct., p. 182): 



Oez 3DC 315 021 002 

007 303 076 015 

007 305 041 132 007 

C07 310 167 

007 311 257 

OCT 312 006 004 

CC7 3U 054 

007 315 167 

007 316 005 

007 317 302 3U 007 

007 3^2 0^1 133 0D7 

C07 325 176 

007 32* 247 

007 327 312 355 007 

007 332 065 

007 333 056 136 

007 335 064 

007 336 156 

0D7 337 046 0C6 

C07 3i1 176 

007 342 376 200 

007 3U 312 000 000 

0C7 3i7 31 5 000 007 

007 352 303 322 007 

0C7 355 315 HO 005 

007 360 303 322 007 



(start *6 



Call TV Emas 



Spaefl 



015^ 60JPM, 010= 100JPM 



'lA 




(REsat all Pointars) 



I A= fullncaa ] 
[ Ekpty? "^ — yes — 



I H= M-1 



r M=""M+1 



fWd H 



I A - Hetgdry 



I Set ?lag 



(Increment R*ail Poiatar) 

(Buffsr Page) 
(Mssflage I-etter) 



¥** e-^ (Es^it to Op. System) 



j Jump Do Agaln^ 

I Call '^Y ^° W 
I Jump Do Agala [ 



1. Page 186, col. 4, lines 16 and 17, 
should read, "nect the square wave 
input from pin 1 of the UOiQ44;' . 

2. Page 186, col. 4, line 32, should 
read, "MC4044 as shown. The out-". 

3. Page 188, col. 4, lines 36 through 



3S, should read, "generates a square 
wave output, In cases where the vco 
generates sine waves or other wave ". 

George R. Allen W2FPP 
161 Rosendale Drive 

Binghamton NY 13905 



Ham Help 



I have been interested in ham radio 
for the past couple of years. I current- 
ly hold a Citizens Band license, but I 
am totally disenchanted with that 
type of communication. I have been 
studying on my own and have no 
trouble with the technical aspect of 
the license. But the code has been 
very disheartening. I would like to 
know if there are any clubs that give 
Morse code classes in my area. Or if I 
could meet or contact amateur radio 
operators who would be willing to 
help. Any and all help will be deeply" 
appreciated. 

Ed Rojas 

Box 490 

Union City NJ 07087 

Help! 1 purchased a Halticrafters 
Tornado SR-500 SSB 500 Watt 
BO-40-20 rig and need help finding 
someone who carries the 8236 final 
amplifiers. Can't find listing in 
Sylvania, RCA, Amperex, or other 
tube makers. Where can you get these 
8236s and what is their cost (under- 
stand Hallicrafters is no longer in 
business)? 

Also, if anyone has iv^fontiation on 
modifications, improvements, 
changes, etc., to the SR-500, 1 would 
appreciate their writing to me. Can 
the 323Bs be subbed for (for example, 
with a pair of 6146Bs with only 200 
Watts PEP instead of 500 Watts)? 

Any assistance from other hams 
would be appreciated. Thanks. 

Man/in Jack Moss W4UXJ 

P.O. Box 28601 

Atlanta GA 30328 

With the ever-increasing use of elec- 
tronics in hospitals and related health 
care facilities, there has been a large 
influx of EE and E Techs to provide 
repair and calibration for the medical 
electronic equipment that lies scat- 
tered throughout these establish- 
ments. It is my guess there must be 



several hundred amateur radio oper- 
ators .hidden within these ranks. With 
the help of your column, I would like 
to compile a listing of all licensed 
amateur radio operators employed by 
"hospitals/health care facilities/medical 
electronic equipment manufacturers 
and service centers. 

Interested hams'shotJld send their 

name/callsign/QTH to my attention. 

Dave Miller WA4ZKZ 

721 Due West Ave. 

Apt. G 202 

Madison TN 371 15 

I am the proud owner of a Sumner 
Model HCV-1B SSTV Camera and a 
Model HCV-2A SSTV^ Monitor, 
neither of which are operating satis- 
~factorily. I urgently require a copy of 
the circuit diagrams and component 
listing of these units. 

Ken Squires VK2SD 

1 Simpson Street 

Bondi, N.S.W.2161 

Austral ia 

Help! I am looking for manuals for 
the following low band radios: Motor- 
ola Model L4IG-1A — this is an ac 
base; Motorola Model T71-GKT 
1 lOOB - low band 1 2 V dc mobile. If 
anyone has manuals or schematics for 
the radios, a copy would be appre- 
ciated. Please drop me a line. 

Ron Luia WB9WX0 

5S42S Meadowview Ave. 

South Bend IN 4662S 

I need the tube test data for the 
TV-4 tube tester. This is part of the 
USM-3A. Will buy or copy. 

Gary P.Cain W8MFL 
2464 Hand Rd. 
Miles Ml 49120 

Would like to hear from anyone 
who has a National ANA^VRR^. 

K. K. Maxwell K5BA 

623 Ute Drive 

Stillwater OK 74074 



81 



David J. Broivn V19CGI 
RR5, Box 39 
NobisBville IN 46060 



CB to OSCAR 



- from 10 to the sky! 



This article describes how 
to convert a specific 23 
CB radio for use on the 
OSCAR satellites and gives 
you my ideas on an OSCAR 
1 meter bandplan very much 
like that of W4NVH in the 
May, 1977, issue of 73 
Magazine, p. 106. (He cov- 
ered the 28 MHz portion of 
10 meters, but used the same 
channel and conversion of CB 
gear principles.) If you read 
that article, you will see that 
the method applies very 
nicely to many of the now 
very inexpensive 23 channel 
CB rigs. The more i read 
W4NVH's article, the more 
things I could find that di- 
rectly applied to the Sears 23 
chanhel Model 934.36740500 
CB I already had. 

The CB channels have a 
fevk' blanks between the 23 
channels (remote control, 
etc.) that are taken care of by 
one each of the transmitter 
offset oscillator crystals and 
receiver offset oscillator 
crystals. In my transmitter, 
the crystal frequencies of 
10.595, 10.615, 10.625, and 



10.635 MH/_ are used, and, in 
the receiver, 10.140, 10.160, 
10.170, and 10.180 MHz are 
used- Following a numbers 
progression, the oddballs are 
obviously the 10.595 and 
10.140 crystals. !n order to 
maintain continuous cover- 
age, I changed the 10.595 to 
10.605 MHz and the 10.140 
to 10.150 MHz. Then I had a 
synthesis scheme capable of 
230 kHz coverage in 10 kHz 
steps. 

Considering that the 
OSCAR 6 and OSCAR 7 
combined bandwidth is only 
150 kHz, and further con- 
sidering that an AM or 
AM/SSB mode (even when 
CW keying is added) would 
not be at all welcome above 
146.000 MHz, my bandplan 
starts at 146 MHz and works 
downward. A couple of 
unique quirks came out of 
that fact. They alone might 
add merit to the bandplan, 
when using CB radios. The 
first is that, when you con- 
vert a CB radio over to the 10 
meter band for transmit and 
receive, two things happen. 



The receiver winds up being 
in the 10 meter downlink, 
where it belongs, by only 
changing crystals and re- 
peaking a very few front end' 
stages [on signal, if need be — 
for those of you with little 
building experience and test 
equipment). - - 

On transmit, the trans- 
mitter signal output is on 1 
meters to go to the up- 
converter, and, believe me, 
just about every commer- 
cially made transvcrter uses a 
10 meter input. 1 know, 
because I have spent two 
years trying to find a Drake 
TC-2 to go with my Drake 
TR-6 to get up to 2 meters. 
Unfortunately, the Drakes run 
a 14 MHz i-f out of the TR-6 
and into the TC-2, negating 
using anything but Drake's 
TC-2. Couple this to very few 
TC-2s having been made at all 
(that's when Drake dumped 
their VHF line altogether, 
leaving us at the mercy of 
imports), and you can 
appreciate my problem. 

Another transmitter bene- 



fit is that the transverter 
winds up being 116.45 MHz 
— exactly the OSCAR offset 
through the translator in re- 
verse. So, when yoi: tune the 
receiver, you are tracking the 
transmitter right along with 
you, plus or. minus Doppler. 
As for Doppler, the CB 
manufacturers never could 
get together to decide on 
what channel they were trans- 
mitting or who was on the 
channel frequency and who 
was off- So, manufacturers 
include a little control on 
most panels now, marked - 
delta - i.e., a Doppler con- 
trol. 

As for the bandplan, if 
you begin at 146 MHz as the 
29.55 MHz downlink (or 146 
MHz uplink), the cardinal 
frequencies of 29.5 MHz and 
29.4 MHz (OSCAR 7 band 
edges) jusf happen to fall on 
channel 19 and channel 9 
respectively. 

Plug ill the new synthe- 
sizer crystals X-1 to X-6 and 
change the offset crystals 
X-10 and X-1 4 to pull the 
band together. Then peak up 
the synthesizer -output tank 
(T8 in mine). C37, across the 
primal y in the Sears, may 
have to be reduced in capac- 
ity slightly, if the synthe- 
sizer output transformer lacks 
enough tuning ran^c- Now, 
with the new synthesized 
-Treciuencies from 39.955 to 
40.155 MHz coming out of 
the synthesizer, feed a 10 
meter signal (signal generator 
or off air) into the coax 
fitting. Align the 10 meter 
(was 27 MHz) front end re- 
ceiver coil(s), which are T1 
and T2 in mine, by backing 
out the slugs a bit and tuning 
for maximum age, signal, etc. 
Do not touch any other re- 
ceiver tuning, assuming the 
rig is new and/or properly 
aligned for CB frequencies. 
The i-fs do not change. For 
CW reception, the easiest way 
is build a little 455 kHz vco, 
so you can "pot" control it 
with dc from outside the 
radio and not botch things up 
by drflling holes in the panels. 
Assuming you like channel- 
ized transceiving as little as I 
do, you can build a second 



82 



vco on the synthesizer fre- 
quency, or some submultiple 
of it and multiply, and run it, 
too, from an outside pot. 
After all, it is no longer a CB 
radio, so vfo/vcos are iegal. hi 
my own, 1 kept the crystals in 
the X-3, X-4, X-5, and X-6 
positions (but at the new 
frequencies shown), and a vco 
runs into the X-1 position, 
with X-2 a blank. This way 
you can run the vco from 
39.955 MHz to 40.155 MHz 
using a ten-turn pot for 
vernier action and, by switch- 
ing from channel 1 through 4 
positions, cover the entire 
29.32 to 29.55 MHz range on 
receive and have the proper 
transmitter frequencies to up- 
con vert to 145.77 to 146 
MHz. With the lower edge 
below OSCAR, you are about 
in 2 meter AM land. With the 
same synthesizer schemes 
used by so many rigs, even an 
AM/SSB (23 channel version) 
is cheaper now and would 
really be a great way to go, if 
you want the SSB mode 
through OSCAR and can 
afford an extra few bucks. By 
allowing the vco to tune 
down to 38.185 MHz (or 
shifting it to cover 230 kHz 
there, as 39.185 to 39.405 
MHz — with a small C 
switched in?), you can have a 
dandy 145 to 145.230 MHz 
out of the trans\'erter and be 
right with the 2 meter SSB 
gang. Add a small 2 meter to 
10 meter converter (Ham- 
tronics makes a great one), 
using the same 116.45 MHz 
oscillator offset, and you 
have a rig as versatile as the 
most expensive ones designed 
for OSCAR and 2 meter gear 
on the market. 

The transmitter conversion 
is just about as tough as the 
receiver — in other words, not 
at all. In mine, once the 
receiver was done {hence, the 
synthesizer), it involved 
peaking up the old 27 MHz 
transmitter stages to the 10 
meter band by backing out 
the slugs a little and, where 
needed, reducing the tuning 
capacitors across the trans- 
formers, when the slug had to 
be backed out too far to be 
practical (slug showing out of 







Equiv. 2m 












New Channel 


Freq. 


Freq. + 116.45 


Synthesizer 


Transmit osc. 


Receive osc. 


Note 


1 


29.32 


145.77 


XI 39.955 


X1 1 10.635 


X7 


10.180 




2 


29.33 


145.78 


XI 39.955 


X12 10.625 


X8 


10.170 




3 


29.34 


145.79 


XI 39.955 


X13 10.615 


X9 


10.160 




4 


29.35 


145.80 


XI 39.955 


X14 10.605 


XIO 10,150 




5 


29.36 


145,81 


X2 39.995 


XII 


X7 






6 


29.37 


145.82 


X2 39.995 


X12 


X8 






7 


29.38 


145.83 


X2 39.995 


XI 3 


X9 






8 


^9.39 


145.84 


X2 39.995 


X14 


XIO 






* 9 


29,40 


145.85 


X3 40.035 


Xll 


X7 




r— Band edge 7 


10 


29.41 


145,86 


X3 40.035 


X12 


X8 




11 


■.!9.42 


145.87 


X3 40.035 


X13 


X9 






12 


29.43 


145.88 


X3 40,035 


X14 


XIO 






13 


29.44 


145.89 


X4 40.075 


XII 


X7 






14 


29,45 


145.90 


X4 40.075 


X12 


X8 


Beacon 6 


j^ Band edge 6 


15 


29.46 


145.91 


X4 40,075 


XI 3 


X9 






16 


29.47 


145.92 


X4 40.075 


X14 


XIO 




1 


17 


29,48 


145.93 


X5 40.1 15 


Xll 


X7 






58 


29.49 


145.94 


X5 40.115 


X12 


X8 




^— Band edge 7 


M9 


29.50 


145.35 


X5 40.115 


X13 


X9 


Beacon 7 


20 


29.51 


145.96 


X5 40.1 15 


X14 


XIO 






21 


29.52 


145.97 


X6 40.155 


Xll 


X7 






22 


29.63 


145.98 


X6 40.155 


X12 


X8 




1 


23 


29.54 


145.99 


X6 40.155 


X13 


X9 




i 


24 


29.55 


146.00 


X6 40.1 55 


X14 


XIO 




"— Band edge 6 



Table 1. CB radios to OSCAR band pi an for a Sears 934.36740500. All figures in MHz. Xmit: 
Fsynth - Fxmit osc = four MHz; Rev: Fsynth - Fin - Frcv osc = .455 MHz Lo i-f. 



the coil form). In my radio 
this involves T12-C69, T13, 
T14-C72, T15-C77, T15-n4, 
T17, and T18. This is 
as easy as tuning up the 
average Heathkit for the same 
reasons, because the test 
equipment is built in the 
form of a built-in wattmeter 
(rf output) and swr com- 
bination meter function in 
transmit. Incidentally, when I 
said peak the receiver for 
maximum age on an incoming 
steady signal, 1 had an S- 
meter in my radio to measure 
that by. 

In the extraneous depart- 
ment, the rig I have has a 
noise limiter that works 
pretty well as is, so I left that 
alone. It also has a PA 
position that can be put to 
good use. Since mine is an 
AM only rig, I had only CW 
in mind. The modulator- 
audio stages in the transmit 
mode (they are shared) can 
be put to use by placing them 
in PA (which routes the audio 
to that jack from the receiver 
as well) and then causing the 
low audio stages to be an 
oscillator at some pleasant 
tone. Or you could use a 
separate tone oscillator, so 
that when you key the rig, 
you have sidetone. On the 
AlVl only rigs you might as 



well, because AM is not very 
v/elcome through OSCAR 
because of its unnecessary 
BW. 

On the subject of keying, 
since this is an AM rig only, 
the -s- voltage for the mod- 
ulation is broken away from 
the modulation winding of 
the common audio trans- 
former by removing an isola- 
tion diode (D13) and opening 
that path. The + voltage from 
the power supply section is 
routed out to the external ■ 
speaker jack, after taking it 
out of the receiver audio 
output path and putting a 
permanent ground on the low 
side of the speaker. 

While on the subject of the 
speaker, 1 had a problem with 
mine. There is a 10 Ohm 
resistor in series with the 8 
Ohm speaker, whose only 
purpose ! can see is to allow 
them to run one common 
audio circuit, transformer, 
and a lower wattage speaker, 
and to accept the lower audio 
output on the bottom-of-the- 
line sets. This was a 1 W 
3-inch round unit in my 
radio, and it was shorted, to 
boot. 

Part of the reason 1 got the 
radio for the right price was 
that it did not work. It had 
one open copper foil in the 



+V copper, where the shorted 
speaker had tried to make a 
fuse out of it — and it suc- 
ceeded. That is absolutely all 
that was wrong, and I fan it 
as a base by sharing my 
Heathkit supply-for the HW 
202 FM for months before I 
tried working on it. I got 
mine for less than |10, so 

"check your local sources. 

Back to the speaker — 
when I replaced i.tj. 1 got a 
3-inch round, 2 W replace- 

-ment speaker and stuffed a 
small, 2 Ohm V2 W resistor in 
the 10 Ohm spot, I can now 
drive you out of the roorti 
with audio! 

When you plug a key in 
the external speaker jack 
now, the key opens and 
closes the driver and final + 
voltages, and you have a CW 
rig — almost. The microphone 
circuit in my model is rather 
tricky, as it does all the 
changeover (X/R) by voltage 
switching. 1 substituted 
another DPDT switch - 
toggle type — on the same 
panel as the vco synthesizer 
and vco/bfo pots, and used it 
for the transmit position. 
Leave the microphone and 
connections off the switch 
and wire the rest the same, 
just to be rid of the PTT/ 
hold-the-button-do win routine. 



83 



WheJi the key is depressed, the 
LED modulation light comes 
on, as it is activated by the 
same power line as the driver 
and final. It makes a good CW 
monitor, if you like the visual 
types and don't want to add 
the tone oscillator into the 
audio circuits. 

To get the vco lines in and 
out of the radio, mine had a 
Heyco type grommet that 
"bites" the +12 V and 
ground where it goes into the 
back panel through a 3/8" 
hole. Replace it with a 
normal 3/8" rubber grommet, 
and you have a hole you can 
drive a bus through, with 
plenty of room for 6 to 8 
wires- 

Convince your CB "good 
buddy" that he really needs 
SSB or 40 channels, and offer 
him a good trade price for his 
old 23 channel rig. The 
dealers are offering peanuts 
on 23 channel rigs, because 
you can buy a new 23 
channel so cheaply now that 
they can't sell a used one, He 
will end up happy and so will 



you! Or, go see your local CB 
store, and see if he took the 
same bath most dealers and 
wholesalers took, when they 
were stuck with warehouses 
of 23 channel stock, when 40 
channel hit the market. Talk 
it up at your club (and the 
bandplan and see if they 
agree), and then go make an 
offer on 1 or more identical 
units — quantity talks. They 
are great for CD type groups 
in crowded 2 meter FM areas! 

Last, but certainly not 
least, if you are the least bit 
adept at repair work and 
common logic and own just a 
VOM or VTVM, you can buy 
a non-working unit from 
places like Sears Save Shop 
and local radio dealers who 
don't really have much in the 
way of repair facilities. 

Well, I've given you a plan 
of attack, a bandplan so you 
will have company in the 
present wasteland of 10 
meters, a cheap way to get up 
on OSCAR, some hints for 
using my unit, and the source 
for one of your own if you go 



looking. Even schematics and 
manuals are a breeze (unlike 
the old FM conversion days 
when any Motorola manual 
or even a close schematic you 
saw as a ham was yellowed, 
battered, torn, thumbprinted, 
and worn from the use of 
50-plus hams). 

You should know that 
T18, in my rig, is used to 
adjust the output to 5 Watts 
and also that the final device 
used is a 2SC7gg with a 10 W 
hfe of 50 to 90, 150 MHz 
rating with a BVcbo = 80 V, 
BVebo = 5 V, and BV well 
above the rated use! Consider 
the low duty cycle of CW 
versus the AM cycle which it 
was running a steady 5 Watts 
at. I run mine off the high 
regulated 18 V dc and load it 
up (tune) for about 14 W key 
down. I haven't lost a device 
yet, but, to be safe, you may 
want to quit at the manu- 
facturer's (Nippon Electric) 
rated 10 Watts. 

There are only two words 
of caution I will add in 
closing. If you tackle a PLL 



type synthesizer, it's not so 
easy. It can be done — on 
some -■ at some time and 
expense and risk of odd 
products sneaking out. 

My only other comment is 
that you should turn back a 
few issues and read through 
W4NVH's article. It is excel- 
lent background and easy to 
follow and use. You can 
figure out just what kind of 
rig you have, if you already 
have it, and how to apply my 
antics to it. 

Don't try to part-convert 
one to cover 10 meters (say, 
low end, per W4NVH) 
for CD activity and try to 
save a chosen "few" of the 
CB channels for CB use. You 
void the manufacturer's 
approval when you cut into 
the rig, even if you hold a 1st 
class radiotelephone license, 
as I do. You void any war- 
ranty on the rig any way you 
cut it. And you could just 
void your license if you get 
caught with this modifica- 
tion. Pick your band, and 
have fun. ■ 






$ 
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Wasyerbespriz?" 

OK, so you want to save money — can't blame you for that! 

After you have called the 800 numbers, got your "best price," sent your money — what do 
you get? A box. Suppose it doesn't work? {Murphys' law). Ship it bacT^ (at your own ex- 
pense) and wait. Or— two weeks after the warranty expires— so goes the rig . . .what to do? 
And since you got that great discount how much attention will you get? Rotsaruck fella! 
Today's amateur equipment is far more sophisticated than that of even a few years ago, 
and it's getting more so every day. Service becomes an important issue. At CFP we have 
decided to offer you an alternative: If you are willing to pay tfie regular list price on any 
Drake or Yaesu product, CFP will provide an additional 90 days of warranty protection. 
Tliis warranty will be identical with the normal warranty with the exception that we will 
pay all charges including shipping both ways.' 

There may be occasions when we won't have the item you desire. Should you place an 
order and we don't, we will refund your money and advise you when it will be available. 
We won't sit on your money! If you wish a high demand item and want to make a deposit to 
ensure getting what you want — fine. 

Because we are amateurs and concerned about the issues, we limit our transmitter and 

amplifiersales to licensed amateurs (a license photocopy will do). 

Amateur radio is a great service and a greater hobby — lets keep it that way! 

Mail Orders accepted. N. Y. residents add sales tax. BASE will get our list of used Amateur Equipment. 



WANTED: GOOD 
CLEAN TRADESI 

WA2KTJ 
WB2LVW 



CFP COMMUNICATIONS, INC. 



211 NORTH IWAIN STREET 

HORSEHEADS, N.Y.14S45 

PHONE: 607-739-0187 



Store Hours 

lues, to Fri. 10-6 p.m. 

Sat. 10-4 p.m. 

FrI, & Sal suojeci lo 
Hamfesl weekends 
Closed Sun. & Men. 



C54 



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84 



START 

YOUR 

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Independent easy to use controls 

CAMERA 

FEATURES: 

Use CI camera with your home TV set 

Has both long distance and close-up features 

Adjustable frame size 

Built-in slo-scan bar gen for transmit 

Focus on a postage stamp 



ACCESSOR J ES: 

PI Polaroid adapter for hard copy photos $34.50 

VI viewing hood $14.50 

T1 tripod $29,50 



Christmas offer 



*Tfiis offer good from November 1 . 1977 to January 15, 1978. 



SS2K KIT 



$195 



or 



SS2 WIRED J58C $245 

CI FAST/SLO SCAN 

CAMERA $395 



AVAILABLE NOW: ORDER FACTORY DIRECT OR FROM OUR DISTRIBUTORS. See Below. 



Germantown Amateur Supply 
3202 Summer Avenue 
Memphis, TN 381 12 

Amateur Electronics Supply 
Milwaukee, Wise. 
Cleveland, Ohio 
Orlando, Fla. 

Argon Electronics 
Miami Springs, Fla. 



A and W Electronics 
Medford, Mass. 

Barry Electronics 
New York, N.Y. 

CFP Enterprises 
Lansing, N.Y. 

Electronic Distributors 
Muskegon, Michigan 



Goldstein's 
Pensacola, Fla. 

Harrison Electronics 
Farmingdale, N.Y. 

Henry Radio 

Los Angeles, Calif. 

Hobby Industry 
Council Bluffs, Iowa 



Mr. Keith Roberts 
P.O. Box 677 
Bedford, N.S. 
Canada BON IBO 

Swartz Lander Radio Ltd 
1524 Oak Harbor Rd. 
Freemont, Ohio 43420 



Venus Scientific Inc. 

The company that put high voltage on the moon, now brings you expanding amateur radio technology. 



399 SMITH STREET 
FARMINGDALE, N.Y. 11735 
PHONE 516-293-4100 
TWX 510-224-6492 

V3 



85 



Fig. 1. Two stations must "see" the satellite's transponder 
simultaneously in order to communicate with each other, i.e., 
they both must be located in the area "illuminated" by the 
satellite. Note that a transponder located on the moon will 
allow communication with stations separated farther apart 
than a satellite orbiting the Earth at lower altitude. 



Kazjmiera J. Deskur K2ZR0 
P.O. Box 11 
Endicott WY J 3760 



7 ' 

/ A. 



/ / 



■ BY r-^ .V,OON 





AREA 'ILLUMIWATCD' BY THE SATELLITE 



Track OSCAR 8 ! 



-' step'by-step method 



he launching of the 
AMSAT OSCAR 6 and 



7 satellites gave amateur radio 
a permanent foothold in 

MAX. NORTHERLY LATITUDE 
(180' 1 = 81°) 



space communication. In 
years to come, satellite com- 



SATELLITE 



SUBSATELLITE POINT 
(15 MIIM. AFTER EQX} 



TIME MARKS 



EOX POSiTION 
(ASCENDING NODE) 




EARTH TRACK 
(SUBSATELLITE TRACK) 



ANGLE OF 
INCLINATION ( 



SATELLITE ORBIT 
OF PERIOD (P) 
102,79 M IN. 



Fig. 2. Model of orbiting satellite (static Earth). 



munications will become as 
common as 2m FM or DXing 
on 20m is today. 

Although there are now 
thousands of users of 
OSCARs 6 and 7, they repre- 
sent only a very small frac- 
tion of the total, amateur 
community-. Why is it that so 
many VHFers who own 
perfectly suitable equipment 
never worked through 
OSCARs? 

Apparently, the major 
deterrent is the lack of famil- 
iarity with satellite tracking, 
which many consider to be a 
formidable and complex 
problem requiring knowledge 
of astronomy, astrophysics, 
higher mathematics, and 
other disciplines of science. 
But, in fact, satellite tracking 
is a relatively simple pro- 
cedure easily grasped by 
those who show even a slight 
interest in this subject. 

The purpose of this article 
is to explain the procedure of 
satellite tracking from the 
standpoint of common sense 
and simple reasoning. I sug- 
gest that the reader follow 



86 



the presented sequence of 
reasoning step by step and 
not go to the next paragraph 
before the previous one is 
fully understood. 

Space communication is 
the future of amateur radio. 
We might as well get famiiiar 
with it, and the knowledge of 
satellite tracking is the first 
step. 

The First Earth Satellite — 
The Moon 

Let's suppose that an 
OSCAR transponder was 
placed on the moon. Using 
suitable equipment, we could 
communicate through it the 
way we communicate via 2m 
repeaters. Since VHF waves 
don't bend around the curva- 
ture of the Earth, we may 
assume that the lunar tran- 
sponder can be accessed only 
if the moon is above the 
horizon in respect to the 
stations that attempt to 
communicate through it. 
Obviously, a two-way QSO 
between distant stations can 
only take place if both sta- 
tions have the moon in direct 
view. 

Without any knowledge of 
astronomy, we can guess that 
at a particular instant of time 
the moon will be visible in 
different directions, and at 
different angles above the 
horizon, in different parts of 
the world. Also, there will be 
locations on the Earth where 
the moon wiil not be visible 
at all. 

With the combination of 
the revolution of the Earth 
and the orbiting of the moon, 
the prediction of its exact 
celestial position, at a particu- 
lar day and hour for a chosen 
geographical location, repre- 
sents apparently a very 
complex problem. Neverthe- 
less, this "difficulty" was 
solved thousands of years ago 
by ancient astronomers 
before trigonometry, cal- 
culus, computers, and even 
writing were invented. 

The artificial satellites, 
such as the OSCARs, behave 
very much like a moon with 
the following small differ- 



erices: 

— Artificial satellites 
are too small to be visi- 
ble to the naked eye, so 
their positions can only 
be predicted. 

— They orbit the Earth 
at the rate of hours per 
revolution instead of 
weeks. This implies that 
their rising and setting 
at a particular location 
of the Earth will be 
more frequent. 

— They orbit at low 
altitudes; therefore, the 
range from which two 
stations can "see" a 
satellite simultaneously 
will be much shorter 
(see Fig. 1 ). 

Terminology 

In order to better under- 
stand satellite tracking, we 
must form a three-dimen- 
sional mental picture of a 
satellite orbiting the Earth. A 
globe or any spherical object 
(even an orange) will greatly 
facilitate the comprehension 
of the subject. 

In order to simplify the 
analysis of the orbital flight 
of the satellite, we are going 
to assume, for a while, that 
the Earth \s static, i.e., it does 
not rotate on its axis. Once 
the static Earth concept is 
well understood, the intro- 
duction of the Earth's rota- 
tion, to complete the picture, 
will not present much diffi- 
culty. Fig. 2 shows a view of 
a satellite orbiting the static 
Earth. The orbit is circular. 

At this time, familiariza- 
tion with the principal param- 
eters of orbital flight and 
related terminology is neces- 
sary because it will be used 
throughout the remainder of 
the article. 

Orbit: The imaginary track 
of the path the satellite fol- 
lows around the world. The 
plane of the orbit is fixed in 
space and is independent of 
the rotation of the Earth. 

Altitude (H): The distance 
between the satellite and the 
surface of the Earth. For sat- 
ellites in circular orbits, the 
altitude is virtually constant. 

Period (P): The time it 




Fig. 3. Simulated Earth track on a plane inclined 99° from the 
equator (static Earth). Note- that the orbital plane is fixed in 
space and the Earth rotates inside this plane from west to east 
(counterclockwise as viewed from a point above the North 
Pole). 



takes a satellite to make one 
full revolution around the 
Earth. The exact moment the 
satellite crosses the equator 
from south to north is used as 
a reference point. The period, 
therefore, is the time elapsed- 
between two such equatorial 
crossings. 

Subsatelllte Point: A point 
on the surface of the Earth 
where the satellite is directly 
overhead. 

Ground Track (also Sub- 
satellite Track): An imaginary 
path on the surface of the 
Earth consisting of all sub- 
satellite points (during one 
period). 

Inclination (i): The angle 
between the equator and the 
ground track (or the plane) of 
the satellite. It should be 
noted that this angle will 
remain constant through the 
entire life of the satellite and 
is not affected by the rota- 
tion of the Earth. 

The angle of inclination 
determines the most nor- 
therly and most southerly 



latitude the ground track will 
ever reach. You may notice 
'That even if the Earth is rotat- 
ing on its axis, the ground 
track will never pass beyond a 
certain latitude. 
--■ Max. Lat. (N, or S.) = 

180° -i 

For OSCAR AO-D: i = 

99° 

Max. Lat. = 180° - 99° 

= 81° N.orS. 

Equatorial Crossing Time 
(EQX Time): The exact time 
in UTC- (GMT) at which the 
ground track crosses the 
equator from south to north. 
Knowing the exact EQX time 
of any orbit and the time of 
the period makes it easy to 
predict subsequent EQX 
times. We simply add the 
period (in minutes) to the 
exact time at which the pr^ 
vious EQX took place. In 
fact, the EQX prediction 
tables published by AMSAT 
and other amateur journals 
are derived this way. 

In order to complete long- 
range prediction tables, the 



87 



OSCARLOCATOR 








Spscia! Thsnks to K2ZH0 

Fig, 4. Static Earth projection of the track of AO-D over the 
map of the Northern Hemisphere. 

period must be known with rapidly. (Example: Period of 
great accuracy, because even OSCAR 6 is 114.99441 min.; 
small errors accumulate OSCAR 7 is 114.94513 min.) 






STATIC 
EARTH' 



OSCARLOCATOR 




r -x- 



special Tf-ant^s .'o K2ZtiG 




^Ufift'^ ^ARTH rK^CK 



FJg. 6. Index scale. After setting the longitude of the EQX of 
the reference, orbit, all longitudes of EQXs of successive orbits 
of the day can be predicted. 




'l'--'^ CD 

"I'D. ^--^ 



5"Pi:;K MAP 



Fig. 5. The effect of the Earth 's rotation on the Earth tracii of 
AO-D. Note that the track is shifted .25° toward the west for 
every minute of satellite travel. The static Earth traci? is shown 
as a clotted line. 



Fig. 7. Time scale. Setting the time of the EQX time of the 
reference orbit opposite index #1 allows prediction of EQX 
times of all consecutive orbits of that GMT day. Note tiiat the 
Earth moving .2^ jmin. will rotate P x .25" during one period 
of the satellite, or 25.7° for AO-D. This corresponds to the 
index mark separation as shown in Fig. 6. Now, If the 
longitude and the time of the reference EQX are set against 
Index marii #7, we can predict both time and longitude of 
subsequent EQXs of that GMT day. 



Equatorial Crossing Longi- 
tude (EQX Lon.): The exact 
longitude on the equator at 
which a particular EQX, from 
south to north, takes place. 
Also called the "Ascending 
Node." 

It will be shown later that 
subsequent EQX longitudes 
are separated by P/4 degrees. 
These figures are also used for 
long-range prediction of the 
EQX data. 

Reference Orbit: The first 
orbit of a UTC (GMT) day, 
i.e., the first orbit that crosses 
the equator after 0000 UTC 
(GMT) from south to north. 

Orbit Number: The count 
of the satellite's full revolu- 
tions around the Earth from 
the instant of the launching. 

Reference Orbit Data: The 
date, orbit number, time, and 
longitude of EQX of a partic- 
ular reference orbit. (Exam- 
ple: Mar. 17, 1978, 10526, 
0012:24, S6.3^) 

Ascending Orbit or Pass: 
The part of the orbit when 
the satellite travels from 
south to north (over either 
the Southern or Northern 
HeiTiisphere). 

Descending Orbit or Pass: 
The part of the orbit when 
the satellite travels from 
north to south. Note: The 
orbit will change from 
ascending to descending at 
the point where the ground 
track reaches its most north- 
erly position (closest to the 
North Pole). The orbit will 
change from descending to 
ascending at the point where 
the ground track reaches its 
most southerly position 
(closest to the South Pole). 

Ascending Node: The 
EQX position (longitude) 
during the ascending part of 
the orbit. It is often used as a 
reference point for orbital 
calculations (see Reference 
Orbit). 

Descending Node: EQX 
position (longitude) during 
the descending part of the 
orbit. 

Developing the Ground Track 
on a Static Earth 

As previously stated, we 
are going to assume at first 
that the Earth is static (non- 




Fig. 8. Calculation of the distance from the tracking station at which the satellite enters the 
area of accessibility (acquisition of signal — AOSJ. ■^ 



rotating). The satellite is the 
proposed OSCAf^ AO-D with 
the following orbital param- 
eters: 

Period: P = 102.79 min. 
Inclination: i = 99° 
Average Altitude: H = 
542 miles (872 km) 
Examining Fig. 2 again, 
let's follow the ground track 
of- the satellite. 

Assuming the reference 
point to be of longitude at 
the equator (ascending node), 
with the gi'ound track in- 
clined to 99° in respect to the 
equator, the satellite will fol- 
low the following path : 



— Starts at longitude at 
the equator (ascending node). 

— Travels northward 
reaching the most northern 
latitude of 81° (180°-i). 

— Begins descending and 
then crosses the equator at 
180° longitude (descending 
node). 

— Continues moving 
southward until it reaches the 
most southern latitude of 
-81". 

— Starts ascending and 
crosses the equator again at 
0° longitude. 

The total elapsed time of 
one such trip around the 



world would be equal to the 
period of the satellite, or 
« 103 minutes. 

If we would slice the globe 
at a 99° angle, in respect to 
the equator, and put both 
halves together again, the 
seam line would follow 
exactly the ground path of 
OSCAR AO-D on a static 
Earth. 

Another way to visualize 
the Earth track is to cut a 
circular hole equal to the 
diameter of the globe in a 
sheet of stiff material and fit 
the sheet over the globe at an 
angle of 99° in respect to the 



89 




Fig. 9. Area of accessibility. The satellite will be available for communication when Its 
subsatellite point is found inside the circle of accessibility. 



equator, as shown in Fig. 3, 
A satellite traveling in a 
circular orbit moves with a 
constant velocity. Con- 
sequently, all equal distances 
v^ill be covered in equal incre- 
ments of time. 

The period of the AO-D is 



103 minutes. Therefore, if we 
divide the entire length of the 
ground track into 103 equal 
segments, each segment 
would represent a distance 
traveled during a time interval 
of one minute. 

I n spite of its good 



Time (min.) 


Lat. 


Long. 


After EQX 






■8 


-27.6 


353.3 


■6 


-20.7 


355.3 


-4 


-13.8 


356.7 


-2 


-6.3 


358.4 





b.o 


0.0 


3 


6.3 


1.6 


4 


13.8 


3.3 


6 


20.7 


4.9 


8 


27.6 


6.7 


10 


34.5 


8.5 


12 


41.3 


11.3 


14 


48.1 


13.8 


16 


54.9 


17.0 


18 


61.6 


21.3 


20 


68.1 


28.0 


22 


74.1 


39.6 


24 


79.1 


61.7 


26 


81.0 


102.1 


28 


78.1 


138.6 


30 


72.7 


157.0 


32 


66.5 


169.0 


34 


59.9 


172.6 


36 


53.2 


176.7 


38 


46.4 


179.7 


40 


39.6 


182.5 


42 


32.7 


184.4 


44 


25.9 


186.S 


46 


19.0 


188.5 


48 


12.1 


190.2 


50 


5.2 


191.8 


52 


-1.7 


193.4 


54 


-8.6 


195.1 


56 


-15.5 


196.7 


58 


-22.4 


198.4 


60 


-29.3 


200.1 



Table 1. 



accuracy, tracking of the 
satellite on a globe is rather 
cumbersome. A flat map is 
much more convenient for 
this purpose. Probably the 
best and most easily obtain- 
able polar projection- map. 
suitable for satellite tracking 
is the OSCARLOCATOR, 
distributed and sold for just 
$1 by the ARRL. This handy 
device can be adapted for 
tracking almost any satellite. 

Let's now project the'- 
static Earth satellite track 
onto the map. Once the track 
is drawn on the globe, includ- 
ing the time marks, its coorjdi-^ 
nates, latitude and longitude 
at one minute intervals, can 
now be drawn at correspond- 
ing coordinates on the map as 
shown in Fig. 4. 

If the track is traced on a 
separate piece of transparent 
material and pivoted on the 
North Pole, it can now be 
rotated to allow the start of 
its origin ((? min. mark) at the 
longitude of any chosen 
equatorial crossing. 

Setting an auxiliary clock 
to read ^0 minutes at the 
exact time of the equatorial 
crossing, we can now follow 
the progress of the satellite 
minute by minute. The time 
on the auxiliary clock will 
correspond to the time marks 
on the track that, in turn, will 
indicate the position of the 
satellite at that very time. 



Obviously, tracking of the 
satellite on the static Earth is 
of little use. Therefore, we 
will now introduce the effect 
of the rotation of the Earth. 

As mentioned previousiy, 
the plane of the orbit of the 
satellite is fixed in space, but 
the Earth rotates on its axis. 
As the Earth rotates, the 
ground track will no longer 
retrace itself during each 
orbit, but will be displaced 
.25 towards the west for 
every minute of satellite 
travel. The rationale is as fol- 
lows: 

— The Earth rotates on its 
axis from east to west 
(counterclockwise as viewed 
from a point above the North 
Pole). 

— The Earth makes one 
full revolution of 360° in 24 
hours or 1440 minutes. 

— This corresponds to 
angular travel of 15° per hour 
(360 "r 24) or 1^ in 4 min- 
utes. 

— In one minute, the 
Earth will rotate .25°. 

Now, how will this affect 
the Earth track developed for 
the static Ear-th,(Fig. 4)? 

In Fig. 5, the static Earth 
track is drawn with a dotted 
line; the true Earth track (for 
the rotating Earth) is the 
solid line. You will hotice 
that the true track is shifted 
.25° for every ^"minute of 
satellite travel. 

For example: 10 minutes 
after EQX, the true track will 
be shifted 2.5° west of the 
static Earth track; 20 minutes 
after EQX - S''; 30 minutes 
after EQX - 7.5°; 51.4 
minutes (half of the period) 
after EQX - 12.85"; 102.79 
minutes after EQX (full 
period) - 25.70°. 

From the last figure, we 
may draw the correct con- 
clusion that after one full 
period, the EQX longitude 
(ascending node) will be 
located P/4 west from the 
preceding one (in this exam- 
ple, 102.79/4=25.70°}. 

The effect of the Earth's 
rotation may be demon- 
strated another way. Using 
Fig. 4 with the Earth track 
(static Earth) drawn on a 
transparent material and 



90 



pivoted on the North Pole, 
we immobilize the track and 
rotate the map counterclock- 
wise at a steady rate. The 
lime checks on the track 
indicate the position of the 
satellite at so many minutes 
after F.QX. If while rotating 
the map vve mark the location 
of substatellite points, we will 
notice that the resulting track 
will look similar to the one 
shown in Fig. 5. 

For example: To establish 
the satellite location 10 
minutes after EQX, we rotate 
the map 2.5°; for 20 minutes 
after EQX, rotate the map 5 ; 
for 30 minutes after EQX, 
rotate the map 7.5^; etc. 

Fortunately, you don't 
have to go to all this trouble 
to develop the Earth track for 
AO-D. For your convenience, 
Tabic 1 lists the coordinates 
for the normalized Earth 
track for OSCAR AO-D. 
These equations were used in 
the preparation of the table: 

(11 

■ Latmicle » arc siti [ (sin i) sin (360 T/Pl I 

(21 .,. 

LonttitiitiH - ore cos ';cos(36Q I /P) y cos B] I- — 

where: i = orbit's inclination 
to equator, P = satellite 
period, T = time after EQX 
(ascending node), and - 
latitude (result of equation 

1). 

Note: Equation 2 minus 
the last term (T/4) will cal- 
culate longitudes for the 
Earth track on the static 
Earth. Equation 1 is valid for 
both the static and rotating 
Earth. 

Employing the above 
formulas, the Earth track of 
any satellite in a circular orbit 
can be easily calculated using 
a simple scientific calculator, 
as long as its period and 
inclination are known. 

To use the device, we take 
published EQX data (time 
and longitude) of a chosen 
orbit. Align the zero minute 
mark of the pivoting trans- 
parent ground track on the 
equatorial longitude of the 
EQX. Start the dock at W 
minutes at the time of EQX 
and follow the satellite's 
progress minute by minute by 
relating the time marks on 




■■ a:v /<.•■.■■■ ■ 







&m^. 



Fig. 10. Calculation of the distance from the tracl?ing station at which the sate/lite is located 
20° above the horizon. 



the track to the time incji- 
cated on the clock. 

Successive EQX Index Scale 

We learned that the longi- 
tudes of successive equatorial 
crossings are separated by 
P/4° (25.70° for AO-D in 
which the period is 102.79 
min.), and that in order to 
predict the EQX of the next 
orbit, we must add that value 
to the EQX longitude of the 
previous pass. 

This process can be easily 
"automated" by adding a 
circular scale to be located 
under the map and pivoted 



on the North Pole. The scale 
consists of index marks 
separated by P/4° and num- 
bered from 1 to 14. We will 
consider index mark number 
1 as a reference and use it as a 
starting point for calculations 
of EQX longitudes of all 
satellite orbits of one full 
UTC (GMT) day (see Fig. 6). 

Obtaining the data of the 
reference orbit of a chosen 
day. We align both the origin 
of the ground track arid the 
longitude of the reference 
orbit against index mark #1 
on the index scale. 

Now, without disturbing 



the position of the map and 
the index scale, we can pivot 
the ground track and set its 
origin on the successive index 
marks and read the value of 
the longitude of the equator 
on the map. These will be the 
EQX longitudes of successive 
passes of the satellite. 

In this way, we are able to 
predict EQX longitudes and 
follow the satellite's ground 
track over the Northern 
Hemisphere throughout the 
entire day. 

EQX Time Scale 

We also learned that the 



91 




Fig. 1 1. Circles of equal elevation in respect to tracking station 
located at A. 



time of the successive EQX 
can be predicted by adding 
the value of the period of the 
satellite to the actual time of 
the previous EQX. For 
OSCARs 6 and 1, with 
periods almost exactly 1 1 5 
minutes, it was a relatively 
simple procedure: Two hours 
were added and then 5 min- 
utes were subtracted. For 
OSCAR AO-D, with a period 
of ~103 minutes, such cal- 
culations are a little more 
cumbersome and prone to 
frequent mistakes. 

In order to simplify this 
problem, a rotary time scale 
has been added. It is placed 
between the map and the 
previously described index 
scale (see Fig. 7). The cir- 
cumference of the scale 
(360°) is divided into 24 sec- 
tions of 15 , each corre- 
sponding to 1 hour of Earth 
rotation. The hour segments 
cati further be subdivided 
into 10 minute intervals 2.5° 
long. If more accuracy is 
needed, more subdivisions 
can be made; one minute will 
correspond to .25° on the 
scale. 

Now, the setting of all 
scales for the reference orbit 
is as follows: 

— Align the track, the 
map, and the index mark #1 
as described previously. 



— Align the exact time of 
the EQX of the reference 
orbit also against the index 
mark #1 . 

— Now the EQX times of 
successive orbits can be read 
directly on the time scale just 
opposite the corresponding 
index marks. 

Once set for any chosen 
reference orbit of a particular 
satellite, both the map and 
the time scale can be 
cemented together (but not 
too permanently) and will 
not require resetting for a 
period of several months. The 
rationale is as follows: 

— EQX longitudes are 
separated P/4° apart. 

— During one period of 
the satellite, the Earth rotates 
P x .25 (.25 per minute) or 
also P/4 . Therefore, index 
marks spaced P/4° apart will 
correctly indicate the correct 
time intervals between succes- 
sive equatorial crossings. 

— Cementing the map and 
the time scale will imply that 
each longitude of EQX will 
have a specific time asso- 
ciated with it. This can easily 
be verified by consulting any 
long-range orbital predictions. 
You will find that like 
equatorial crossing longitudes 
always occur at the same 
UTC (GMT) time. 

In practice, this relation is 
not that constant. Due to 




Fig. 12. Complete range overlay showing botii azimuth and 
elevation. 



various factors, such as the 
solar year not being exactly 
365 days, ^gravitational pull of 
the moon, etc., a slight drift 
between both scales will be 
noticed over a period of time. 
Therefore, it will be necessary, 
to realign the scale slightly a 
couple times a year if high 
accuracy is required. 

Summary 

An orbital calculator 
described above consisting^ot- 
four scales (the Earth track, 
the map, the time scale, and 
the index scale) provides a 
complete satellite tracking- 
system, as long as ttne data of 
the reference orbits are avail- 
able. The system allows pre- 
diction of EQX times and the 
longitudes of all successive 
orbits of that day. In addi- 
tion, this system permits 
tracking the exact position of 
the sateliite during the entire 
24 hour period when the 
spacecraft is passing over the 
Northern l-Jemisphere. 

Azimuth/Elevation Overlay 

J ust to be able to track a 
satellite in respect to the 
Earth is not sufficient for an 
OSCAR user. Since the com- 
munication via satellite is 
only possible when the satel- 
lite is within the "view" 
(above the horizon) of the 
tracking station, the user 
must be able to predict the 



rising and setting of the 
spacecraft at his geographical 
location. iVloreover:, if direc- 
tional antennas are used, the 
azimuth (bearing) and the 
elevation (angle above the 
horizon) of the satellite in 
reference to the communicat- 
ing station must be known at 
all times so the- antenna can 
be aimed directly toward the 
orbiting transponder. 

Communication Range 

Fig. 8 depicts, diagramati- 
cally, the Earth and the orbit 
of the satellite.' "Both are 
drawn to scale. The Earth 
radius is 3960 miles (6371 
km), and the average altitude 
(H) of AO-D is 542 miles 
(872 km). Consequently, the 
radius of the orbit will be 
450'2 miles (7243 km). 

Point A in Fig. 8 repre- 
sents the QTH of the user and 
the horizontal line represents 
the horizon as viewed from 
point A. As long as the path 
of the satellite lies below the 
horizon, the bulk of the 
Earth will prevent radio 
waves from reaching the 
transponder and no com- 
munications will be possible. 

At the very moment the 
satellite crosses the local hori- 
zon, it will become "visible" 
to the user and two-way 
communication through the 
spacecraft's transponder will 
be possible. It stands to rea- 



92 



son that at the instant the 
satellite sets below the hori- 
zon, the communication via 
its transponder will be 
abruptly terminated. 

With the aid of Fig. 8, we 
can easily calculate the maxi- 
mum communication range 
of OSCAR AO-D. Point B orr 
Fig. 8 represents the location 
of the satellite just crossing 
the local horizoin of a station 
located at A. A straight line 
drawn between B and the 
center of the Earth will inter- 
sect the surface of the Earth 
at point C, which becomes 
the subsatellite point of the 
spacecraft just rising above 
the horizon. 

It becomes evident that 
the distance AC on the sur- 
face of the Earth is the 
maximum distance from 
which the satellite will be 
visible from point A. In other 
words, as long as the subsatel- 
lite point of the spacecraft is 
no further away than distance 
AC, the satellite will be 
within communication range 
of a station at point A. 

The distance AD, on the 
surface of the Earth measured 
in Great Circle degrees, is the 
angle AOC. Careful measure- 
ments of this angle, or mathe- 
malical calculations, will 
show that for OSCAR AO-D^ 
this distance is 28.4'' Great 
Circle degrees (1 Great Circie 
degree equals 69.1 statute 
miles, or 1 1 1 .2 km). 

Therefore, we may con- 
clude that as long as the 
subsatellite point of AO-D is 
found within a circle with the 
radius of 1963 miles (3159 
km) from the user's QTH, the 
satellite will be available for 
communication. 

This circle of accessibility 
is easily plotted on the globe. 
Using a compass, measure the 
distance of 28.4 (using longi- 
tude markings on the 
equator) and inscribe a circle 
centered on the user's QTH 
(Fig. 9). 

Two stations communicat- 
ing with each other must have 
the satellite in view simulta- 
neously. Therefore, their 
areas of accessibility must 
overlap. Also, the satellite 
must be passing through that 




SET REFERENCE ORBIT DATA HERE 



Fig. 13. Complete tracking system. Example: Reference orbit — 0032 GiViT, longitude 57.2°. 
Set these values against index #7. We want to track A 0-D during 14th orbit Under index #74, 
we read EQX data: time 2247 GMT, longitude 31.8° . Tracking: satellite AOS (acquisition of 
signal) 10 minutes after EQX, 90° azimuth. 15 minutes after EQX — azimuth 45°, elevation 
~ 8°. LOS (loss of signal) 20 minutes after EQX, 10° azimuth. 

angle AOC is its distance 
from A in Great Circle, 
degrees. 

Using a graphical method, 
or mathematical calculations, 
distance AD can now be cal- 



overlapping area in order to 
be visible from both QTHs at 
the same time. With this in 
mind, we may conclude that 
the maximum theoretical 
separation between two dis- 
tant stations capable of 
communicating via AO-D will 
be 2 X 28.4° = 56.S Great 
Circle degrees or 3926 miles 
(6318 km). 

Equal Elevation Range 

Using a procedure similar 
to the one described above, 
we may plot distances from 
which the satellite will be 
seen at a constant elevation 
angle above the horizon in 
respect to point A. Fig. 10 
shows how it is done. 

Angle BAD is the angle of 
the satellite above the hori- 
zon, say 20°. Point C is the 
subsatellite point at this ele- 
vation. Consequently, the 



ciliated. As in the" previous 
^e.xampie, a circle correspond- 
ing to that distance can be 
drawn on the globe. Repeat- 
ing this procedure for differ- 
ent values of elevation angles. 



Elev. 




Distsn 


ce 


Angle 




Mile$ 


Km 





28.4 


1962 


3158 


t 


27.4 


1893 


3096 


2 


26.5 


1831 


2947 


3 


25.5 


1762 


2836 


5 


23.8 


1644 


2647 


10 


20.0 


1382 


2224 


15 


16.8 


1161 


1868 


20 


14.3 


988 


1590 


30 


10.4 


719 


1156 


40 


7.6 


S25 


845 


50 


5.6 


387 


623 


60 


3.9 


269 


434 


70 


2.5 


173 


278 


80 


1.2 


S3 


133 


90 












Table 2. Distance between subsatellite point and tracking 
station at different elevation angles. Note that even a small 
topological obstacle that elevates the horizon angle by 3° will 
shorten the distance of accessibility by 200 miles. 



93 



a family of concentric circles 
can be plotted, each repre- 
senting a different angle of 
elevation (Fig. 11), 

Elevation angles as a func- 
tion of distance from the 
user's OTH for OSCAR AO-D 
are given in Table 2. You may 
observe, by examining Table 
2, that even a small loss of 
low angle radiation due to 
topological configuration of 
one's QTH may result in sub- 
stantial loss of the maximum 
communication range. 

Azimuth Lines (Bearing) 

Once the circle of accessi- 
bility is drawn on the globe, 
the azimuth, or bearing, lines 
can easily be added. 

If, for example, we want 
to draw azimuth lines every 
15°, we divide the circumfer- 
ence of the circle of accessi- 
bility into 24 equal parts and 
draw straight lines toward the 
center of the circle as shown 
in Fig. 12. If azimuth lines at 
10° intervals are needed, the 
circle must be divided into 36 
equal parts. 



Projecting Azimuth/Elevation 
Overlay on a Flat Map 

Once the azimutli/eieva- 
tion overlay is drawn on the 
globe, it can be transferred on 
the circular orbital calculator 
described previously. 

This is accomplished by 
transferring coordinates 
(longitudes and latitudes) of 
various points of the overlay 
from the globe to the corre- 
sponding coordinates of the 
flat map. The result will be an 
elliptical overlay with curved 
azimuth lines as shown on 
Fig. 13. 

Due to projection distor- 
tion, the shape of the overlay 
will be different for different 
latitudes of the user's QTH — 
circular for North Pole and 
quite elliptical for points 
close to the equator. It 
should be rioted, however, 
that the overlays v/ill be 
identical in shape for QTHs 
located at identical latitudes. 

Notes 

1. A globe produced by 



the National Geographic 
Society comes equipped with 
a transparent "cap." If the 
azimuth/elevation overlay is 
drawn on the cap, it can 
easily be centered on any 
chosen location of the globe 
allowing instant determina- 
tion of coordinates for 
azimuth and elevation points 
from that location. 

2. Those who possess a 
so-called "azimuthal equidis- 
tance projection map" 
centered on (or very close to} 
his own geographical location 
can use it easily for plotting 
the azimuth and elevation 
overlay and don't have to 
resort to the more cumber- 
some globe. (The ARRL DX 
map is of this type and is 
centered on Wichita, Kansas. 
Other maps centered on 
principal cities are available 
from the U.S. Dept. of 
Commerce, Coast and 
Geodetic Survey.) 

Calculations involved in 
the development of the az/el 
overlays are quite compli-. 
cated and involve knowledge 



of spherical trigonometry. 
This subject is beyond the 
scope of this article. 

A circle drawn on the 
northern projection map 
(such as used in the ARRL's 
OSCARLOCATOR) is a 
reasonable solution, if utmost 
accuracy is not required. The 
circle, however, will indicate 
somewhat shorter than actual 
range to the west and east of 
the tracking station. 

Application 

To use the az/el overlay, 
we simply follow the satel- 
lite's progress and determine 
its subsatellite points during 
the pass. 

If the location of the satel- 
lite is found within the 
borders of the overlay, the 
spacecraft is accessible for 
communication. 

Then, the correct antenna 
bearings are determined by 
relating the satellite's position 
in respect to the azimuth/ 
elevation markings on the 
overlay as shown on Fig. 
13." 



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D.J. Lytich W4MNW 
2000-147 Meridian Rii. 
Tallahassee FL 32303 



Build A 2m Power Amp 



- - great for OSCAR uplink 



Class C amplifiers have 
been popular for some 
time for 2 meter use. How- 
ever, to go to the trouble of 
adding an outboard amplifier, 
it must produce enough gain 
to make it worthwhile. A 
minimum of 6 to 8 dB is 



required to make the addi- 
tional amplifier worthwhile 
and 10 dB gain is desirable. 

Many amplifiers I have 
observed, both commercial 
and homebuilt, have used two 
generation old transistors, 
2N5590 and 2NS591, for 



■@ou- 




^ —1/2- NO -^ *1^G 

l^ AF=RQX I 1/2 IN 

LONG TOTAL 



Fig. 1. Amplifier scliematic. C1-C4 — Arco 463, 464, or 424; 
RFC! - lOt it20 on 270 Oiim J/2 Watt resistor; C5 - 3-90 pF 
silver mica in parallel or 2-150 pF uncased miens also in 
parallel; RFC2 — 6 to 8 turns i:18 around toroid core; LI — 
1 [2 turn iil4 approx. V/2 inches long; L2 — 4t ifl4, 1/4" I.D. 
spaced wire diameter; L3 — Curved wire ~I4, 1-1/4" long; Ql 
- MRF238 Motorola rf power trans.; DI-D8 - IN4148; 
T1-T2 — 1/4 wavelength of RG-174 or similar 50 Ohm coax 
cable; D9 — 2 Amp silicon rectifier. 



power levels of 10 to 25 
Watts. There is a much better 
device available in the 25 to 
30 Watt range, the Motorola 
MRF238. For comparison of 
the data sheets of the 
2N5591 and MRF238, see 
Table 1 . 

At 150 MHz, the gain of 
the MRF238 is approxi- 
mately 0.5 dB higher than at 
160 MHz (shown in Table 1). 
The MRF238 is rated at 30 
Watts atid the 2N5S91 is 
rated at 25 Watts. In practice, 
the MRF238 has proven 
much more rugged than the 
2N5591 series (more tolerant 
of high VSWR). The MRF238 
also has higher efficiency. 

The amplifier shown 
schematically and pictorialiy 
in Figs. 1 and 2 respectively is 
not unlike many others; how- 
ever, it makes use of the high 
performance MRF238. 

The performance data in 
Table 2 was recorded for this 




Fig. 2. Photo showing construction of the amplifier. The input 
is via the BNC connector at the top. 



96 



Device 


Voltage 


Ffeq. 


Power In 


Power Out 


Gain 


Voltage 


Power in 


Power Out 


Gain 


2N5591 


13.6 


150 MHz 


2 Watts 


10.8 Watts 


7.3 dB 


13.7 


2 Watts 


26 Watts 


11.1 dB 








4 Watts 


20.5 Watts 


7.1 dB 


13.7 


1 .3 Watts 


1 8 Watts 


11.4dB 


MRF238 


13.6 


160 MH^ 


1.5 Watts 


19.5 Watts 


11.1 dB 
















2 Watis 


24 Watts 


10.8 dB 




Table 2. Perfoi 


/nance data. 










3 Watts 


30.5 Watts 


10,1 dB 











Table J. Comparison of2N5591 and Motorola MRF238. 



amplifier. 

A small loss is involved 
with the diode switching. 

The amplifier was as- 
sembled by using single-sided 
copper epoxy board and 
cementing small "islands" of 
board onto the main board. 



The main board is 2-7/S" x 
5" and the minibox is 3" x 
5-1/4" X 2-1/8". A heat sink 
is mounted to the top of the 
minibox. The only critical 
items are LI, L3, and C5. 
Make sure Tl and T2 are an 
electrical 1/4 wavelength, 



approximately 13-1/2" with 
polyethylene coax (RG-174). 
All capacitors should have 
leads as short as possible. The 
amplifier is usable with inputs 
of less than 1 to 2.5 Watts. 

The price of the 30 Watt 
MRF238 is S8.55 in unit 
quantities, which is less than 
the 25 Watt 2N5591 or 



2N6082, another point in its 
favor. 

If all items are bought 
new, the cost is about $23; 
however, with a reasonable 
junk box, it can be con- 
structed for about $12 (the 
MRF238, a minibox, and 
miscellaneous items not in 
the junk box). ■ 



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1 



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Features: CMOS Electronic Keyer 

*SlJ3te-of-The-arT CMOS circiiiTry 

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T18 



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BC-206 



Frequency Counter 

FM - AM - SSB & CW 

Operates with all transceivers 




Frequency range 2,000 kHz to 199.999 MHz 
Display 6 digit W LED display 

• Input sensitivity 100 MV (Si 50 Olims 

• Gate time 80 Ms 

• Stability .001% 

• Source Current SOO mA 

• Max power 200 V/atts 

• Size 1-S/6"H X 31/8"W x 4-3/8"D 

• Fully assembled, not a kit. 

• 3149.50 shipped PP. CA res. add 6% 

NCG COMPANIES 

1275 N. Grove St. 
Anaheim CA 92806 iMio 



97 



E. Dusina VV4NVK 
4724 Ridge Grove Hd. 
KnoxviUe TW 3791S 



Build A 
General Purpose Preamp 

-- uses common components! 



For those of us who are 
engineers, it is relatively 
easy to crank out a custom 
circuit to fit every little need. 
However, most experimenters 
and hams are not in that 
category, and, for them, the 
next best thing is an accumu- 
lation of a few good circuits 
about which they know a lot. 
This article describes a simple 
audio amplifier which has 
high gain, low noise, and 
excellent stability toward 
temperature extremes. 

While it is very simple and 
is used in many commercial 
devices, it can be used in 
almost all those places where 
you need a preamp, such as 
mike boosters, first af ampli- 
fier after a detector stage in a 
receiver, etc. 

Referring to Fig. 1, the 
ci'Xuit can be seen as a direct 
coupled pair of 2i\3904 tran- 
sistors. This transistor is 



cheap, high gain, fairly low 
noise, and very easily ob- 
tained. The Q2 transistor is 
hooked up like any ordinary 
amplifier stage, but the base 
resistor that normally goes 
from its base to ground has 
been replaced with another 
transistor, Q1 . This Q1 tran- 
sistor varies the bias on Q2, 
so the circuit is immune to 
heat effects. The way it's 
hooked up, if Q2 draws more 
current, the voltage on R2 
rises, turns on Q1 harder via 
the 1 00k resistor connected 
to its base, and cancels out 
the increased current in Q2. 
The result is almost no 
change in current due to 
temperature variations. The 
capacitor C2 prevents the ac 
signal from being fed back 
and reducing the overall gain. 
By placing the capacitor as 
shown, a very small value, 
which is also small in physical 




• b -0 18 VDLTS 



JaOlvT -IKfl 



Fig. 1. 



size and cheaper, will permit 
the amplifier to keep its full 
gain to low frequencies as 
well as would be the case for 
a very large C placed across 
R2. The values in Fig. 1 will 
amplify down to about 10 
cycles using a physically small 
capacitor, To make the ampli- 
fier roll off at a higher fre- 
quency on the low side, 
reduce C2 to about 1 uF or 
iess, or, alternately, you 
could reduce the 100k j'e; 
sistor to about 10k. This 
would make the frequency 
roll off around 100 cycles 
and turn the circuit into a 
speech amplifier rather than a' 
hi-fi type. 

The circuit shown in Fig. 
1 performs best when driven 
by a moderate impedance 
source from 500 Ohms to 3k 
Ohms impedance. With this 
kind of source, the gain will 



be about 250, and the output 
noise with no signal in will be 
about 2 millivolts. This is 
equivalent to an input noise 
of only 8 microvolts, so the 
noise is quite low for all but 
extraordinary uses. 

If you wish to drive the 
circuit with a iow impedance 
source, such as a speaker of 4 
to 16 Ohms or a telephone 
earphone (which makes an 
excellent high output mike), 
use the circuit in Fig. 2. Here, 
the base is tied to ground via 
a capacitor, and the signal is 
fed to the emitter of Q1 
through a capacitor. This cir- 
cuit will perform very similar- 
ly to Fig. 1, but will have 
slightly higher gain reaching 
perhaps 500 and about the 
same low noise performance. 

Ten microfarad capacitors 
are used throughout because 
they are small and cheap, and 
are more than enough to do 
the job here. 

This simple circuit can be 
made up in a ball smaller than 
an acorn and put into mikes 
to give you more gain than 
you need to drive even the 
worst transmitter- It also 
works well when driven by a 
speaker put out in the yard to 
let you listen for prowlers at 
night, when you don't care to 
get out of a warm bed, but 
the dog barks like he's on to 
something. Fed into any hi-fi 
input, such a preamp will let 
you hear better than if you 
were out in the yard. There 
are many other uses, and 
most of them will please you 
because the low noise of this 
preamp lets you really hear 
clean audio. ■ 



4fl TO SOOil 




S TC IB VOLTS 



Fig. 2. 



9S 



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H5 



Address- 



Prices are mail order net F.o.B. Benton Harbor, Michigan. 
Prices and specifications subject to ciiange without notice. 



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99 



Bob Shaituck WB3.GCP 
Box 20ZA, Route 1 
Gillsn PA 1 6925 

BiU Schmidt VJB8VQD 
734 N. 1 1 tk Street 
Miamisbwrg OH 45342 



Receive CW With A KIM 



' micro-controlled, of course! 



In the January, 1977, issue 
of 73 Magazine, WB2DFA 
presented a fantostic article 
concerning the use of the 
KliVl-1 microprocessor for the 
transmission of Morse code. 
We have used the program 
repeatedly on the air since 
that time, and it has been met 
with never-ending amaze- 
ment. The KIM was finally 
given a ham-oriented use. The 
next step had to be reception 
of IVtorse, a formidable pro- 
ject hinged on an entire hand- 
ful of variables: Morse code 
was not predictable — speeds 
changed, intra- and inter- 
character lengths were not 
constant, word spaces seemed 
unpredictable, and 
even sending "style" played a 
big part. Could it be done? 
Finally, after much writing, 
rewriting, hotir-long QSOs to 
solve bugs, and a good deal of 
hair-pulling, the program 
worked. 

The reader should be cau- 
tioned at this point that "per- 
fect" reception is nearly 
impossible without "perfect" 
sending. This will rarely be 
encountered, given noise and 
the multitude of sounds 
issuing forth from the CW 
bands. Suggestions will be 



Lsl! ,„, 



Fig. J. Connecting a code key 
to the KIM. 



offered for copying both 
hand key and off the air. 
The program fits comfort- 
ably in the onboard KIM 1 K 
memory. No additional 
equipment is needed for hand 
key decoding. Connection to 
a receiver requires oniy a 
simple adapter, which can 
easily be constructed for 
under $5.00 with readily 
available parts. The program 
allows the option of dis- 
playing the decoded Morse on 
the integral KIM 7-segment 
LED display or having the 
output sent to an ASCII TTY 
or a video terminal. Due to 
the slow speed of a mechanical 
printer, only very slow Morse 
can be decoded. Of course, a 
high baud rate video terminal 
will allov/ the program to run 
at full speed without getting 



- 


"B 


"d 






,D 


i 


J :-- 


.n 


t 


K — \ 


^K 


13 


L ■--. 


^ 


B 


M 


'P 





''n 


"d 



bogged down in the out- 
character subroutine. A video 
terminal usually offers auto- 
matic carriage return/line 
feed at the end of each line. 
Obviously, these functions 
are not part of the Morse 
code and require terminal 
generation. Using the KlJVl 
display allows the decoded 
material to be displayed in a 
"Times Square" format, with 
letters shifting left auto- 
matically with the reception 
of each new letter. The pro- 
gram even offers automatic 
placement of word space 
"blanks" between completed 
words, for easier reading.- --■ 
Finally, the program here 
has run equally well on the 
KIM-1 and also on a 
6502-based home brew. It has 
been tested for several 



"B 



.q. 
'B 



^a 



■a 

a 

•a 

■B 'B 



■B -a 



Fig. 2. Decoded Morse code as it will appear on the KIM 
display. 



months and, we think, does 
the best job possible with 
such an unpredictable code as 
Morse. Using the program on 
a KIM is straightforward. 
Using the program on another 
6502-based system would re- 
qtjire only changes to call-ups 
of KIM subroutines and ROM 
locations. A timer would also 
be required; the KIM has two 
built in. 

A description of how the 
program accomplishes its goal 
is a bit involved. Basically, 
when pushing "Go," you will 
see the six digits on the KIM 
board display random garbage 
which was in locations OOOA- 
000 F when the computer was 
powered up. About half a 
second later, the display will 
shift left one digit, and a 
blank digit will appear on the 
right, ready for the first de- 
coded Morse character. After 
reception has continued for a 
while, these locations will 
hold the last six decoded 
characters. But the micro- 
processor never sits idle. It is 
constantly inspecting pin A-8 
(PA7) for data input from the 
hand key or' optional re- 
ceiving adapter. The program 
loop also checks the onboard 
timer to see if a 4-millisecond 
period has elapsed. Each time 
the timer expires, the loop 
breaks long enough to incre- 
ment location 0001. As- 
suming no code has been re- 
ceived, after about half a 
second, location 0001 has 
been incremented up to hex 
7F. At this time, the loop 
breaks again and jumps to the 
Sh'iFT left display sub- 
routine. Its next move is to 
the zero page conversion 
table. The count in location 
0007 is used as an offset to 
select the proper data in the 
table. 

If, as we are assuming, no 
Morse has actually been re- 
ceived yet, location 0007 will 
still be at its initialized value, 
and an error sign wili be 
called up. This data is placed 
in location GOOF, which 
serves the right-most digit on 
the KIM board. Then location 
0001 is compared to 0005, 
which was initialized to a 
value of hex 01 . Since 0001 



100 




J_' ± 






r 



WOME^JT£»T 
SWITCH' 



Fig. 3. Tone adapter to use the KIM with a receiver. 



will contain a greater count, a 
second trip through the 
SHIFT LEFT DISPLAY and 
the conversion table will be 
accomplished. This time, the 
code for turning all display 
segments "off" will be loaded 
into OOOF. Then the micro- 
processor reinitializes 0007 
and returns to the loop. Also 
set was 0002, which serves as 
a flag for the loop to now 
bypass its checks on the in- 
terval timer. Until actual code 
is received, this final loop will 
be repeated endlessly. The 
visible effect on the activity 
just described is that about 
one-half second after starting 
the program, the random data 
displayed wiil shift left twice, 
with the two right-most digits 
containing an error symbol 
followed by a blank. 

After this has occurred, 
you wili next initialize the 
code speed. This is done 
simply by grounding the in- 
put pin (AS], either by 
holding down the hand key 
or, if you're using the re- 
ceiving adapter, by holding 
down the initialization 
momentary switch. As soon 
as the microprocessor dis- 
covers that the status of the 
input pin has changed, the 
interval timer is put to work 
again. Holding the key/ 
initialization switch down 
about one second will allow 
0001 to again be incremented 
up to 7F. Again the loop 
breaks, but this time a dif- 
ferent path is taken because it 
was [earned that the key was 
indeed "down." Location 
0003 is now set equal to 
location 0001 and will serve 
as a flag to steer the program 
through the initialization 
routine. 

Now, as code is entered via 



the input pin, the program 
increments location 0001 
every 4 milliseconds, to mea- 
sure the length of time the 
key is kept down or up. The 
first key-down is multiplied 
by two (i.e., shifted left once) 
and stored in location 0005. 
Then, it is shifted right two 
times, which effectively 
divides the original count by 
two. This final count gets 
stored at 0006. 

Why get these counts? The 
microprocessor will use suc- 
ceeding key-down counts for 
comparison to those just 
stored. The processor must 
decide which was a dot and 
which was a dash. The first 
count, by definition, was 
either less than half the latest 
count or greater than twice 
the latest count. If the first 
count was a dot, initialization 
is ended. If it was a dash, 
counts in 0005 and 0006 are 
updated with the latest 
count, since proving that the 
original count was a dash 
requires that the latest count 
was of dot length. Initializa- 
tion, then, requires both dots 
and dashes so that a com- 
parison can be accomplished. 
All future counts will be com- 
pared to the one now loaded 
at 0005. Any count less than 
that in 0005 will be con- 
sidered a dot; those counts 
greater will be considered 
dashes. At this point, all the 
computer knows is the dif- 
ference between dots and 
dashes; we still don't have 
characters ! 

So, where does the com- 
puter begin to determine that 
there is intelligence in what it 
is receiving? The magic begins 
to occur in location 0007. 
Every time a dot is received, 
0007 is shifted left Also, for 





Zero page 


7 -segment 


Terminal 


Character 


Address 


code 


code 


A 


15 


F7 


CI 


B 


28 


FG 


C2 


C 


2A 


B& 


C3 


D 


K 


DC 


C4 


E 


12 


F9 


C5 


F 


22 


F1 


C6 


G 


IE 


EF 


C7 


l^ 


20 


f4 


C8 


1 


T4 


BO 


09 


4 


27 


m 


CA 


K 


in 


m 


CB 


L 


24 


BB 


CC 


M 


17 


B7 


CD 


IM 


16 


04 


CE 


O 


IF 


DC 


OF 


P 


28 


F3 


DO 


Q 


2D 


EB 


D1 


R 


lA 


DO 


D2 


S 


18 


AD 


D3 


T 


13 


Fa 


D4 


U 


19 


9C 


D5 


V 


IT 


BE 


D6 


w 


IB 


FE 


D7 


X 


29 


F6 


D8 


Y 


2B 


F3 


D9 


z 


2C 


■C9 


DA 


1 


3F 


86 


B1 


2 


37 


DB 


B2 


3 


33 


GP 


B3 


4 


31 


€6 


B4 


5 


3D 


ED 


85 


6 


40 


,FD 


B6 


7 


48 


S7 


87 


8 


4C 


F> 


B3 


9 


4E 


EF 


B9 





4F 


BF 


BO 




41 


CO 


AD 


? 


5C 


m 


BF 




83 


84 


■^ ., AC 




65 


^S 


AE 


/ 


42 


D2 


AF 


ERROR 


11 


89 


CO 


WORD SPACE 


10 


GO 


AO 



Tabie 1. How to use the table: Decide whether you want to 
have output of the decoded Morse on the KlM's 7-segment 
display or whether you will be using an external terminal (be It 
nv or video). If you want:- --- 

7-segment Display — Load the appropriate data In the 
"7-segment code" column at the specified zero page locations. 
For example, you will be loading data for an "A " by loading 
"F7" at location (jXpiS. Disregard the "Terminal code" 
column. 

Terminal Display! Printout — Load the appropriate data in the 
"Terminal code" column at the specified zero page locations. 
For example, you will be loading data for an "A" by loading 
"CI" at location 0015. Disregard the "7-segment code" 
column. Note: For terminal use, the KlM-1 requires jumpering 
of pin 21 to pin V on the Application Connector. Installation 
of an SPST switch between those points allows switching from 
the KliVt's Integral display to a terminal for IjO. 



each dot detected, a jump to 
a speed adjustment sub- 
routine can be taken, if de- 
sired (described later). Dashes 
shift 0007 left once and add 

(f-J n 

"Key-up" counts must 
also be considered and serve 
to complicate the decoding of 
Morse even more. As long as 



the counts test to be less than 
that count in 0005, the pro- 
gram assumes a single Morse 
character is still in the process 
of being 'sent. But as soon as 
any key-up count exceeds the 
value in 0005, the single char- 
acter is considered com- 
pleted. After a check to see 
that bit 7 in 0007 is not equal 



tOI 



to a one, the program uses 
this value as an offset to the 
zero page conversion table. If 
bit 7 were a one, the program 
recognizes that the letter re- 
ceived could not have been 
IVIorse (no (Morse character is 
7 elements long!) and dis- 
plays the error symbol. Note 
that, in practical use on the 
air, errors are followed by a 
string of dots. The computer 
will advise you of this occur- 
rence! 

We have mentioned the 
data in 0007 as being all- 
important, as it represents the 
actual IVIorse character. Note 
several points: 

1. 0007 will be initialized 
to hex 01 . (This will serve our 
"error" condition stated 
above, if this bit gets shifted 
left to the 7th bit.) 

2. Dots will be entered in 



this location simply by a shift 
left (effectively entering a 
zero). 

3. Dashes will be entered 
as ones, 

Morse character "A" will 
end up in 0007 as "0000 
0101" in binary form. The 
"di-dah" appears in the first 
two places to the right, with 
the initial "one" being shifted 
to the third position from the 
right This code for an "A" 
has a decimal value of "5", 
and the program at location 
025 F uses this value, offset 
by 1 0, to find the code for an 
"A" at 001 5. At this loca- 
tion, a hex F7 has been 
entered, if you planned on 
using the KIM display as your 
output; if you had decided on 
using a terminal and wanted 
ASCII output, a hex CI 
would have been loaded in- 



stead (see Table 1). 

Subroutines are used to 
shift the display memory, 
scan that data onto the dis- 
plays, adjust the code 
speed during actual opera- 
tion, and provide for the 
output of the decoded data 
to a terminal. Any of these 
subroutines may be deleted 
by replacing the appropriate 
JSR instruction with NOPs, 
The first two subroutines are 
required, if the integral KIM 
display is to be used; the 
third is optional, to allow 
automatic code speed adjust- 
ment. If you do not use this 
subroutine, the initial code 
speed will be considered by 
the computer to be the only 
code speed, and it will not 
adjust to speed changes. 
Obviously, if you are re- 
ceiving Morse from a station 



using a keyboard or another 
computer, this speed adjust- 
ment routine will not be 
needed and would only serve 
to complicate matters by 
slowing the program down. 
The JSRs to these sub- 
routines are located at; 
0243 - SCANDS - puts the 
decoded data on the KIM 
display. 

0257 - SHIFT LEFT DIS- 
PLAY - allows the data to 
move "Times Square" format 
across the KIM display. 
02AD - ADJUST SPEED - 
allows the computer to up- 
date the code speed it is 
receiving. 

0263 - OUTCHARACTER - 
allows the computer to out- 
put the decoded character to 
an ASCII terminal. 

For instance, let's say we 
don't want data to be dis- 







i 




DEFINE 

INP(JT£ 


0217 






1 




INPUTS 


c 




1 


-6 




flSL AC 




J 




\ 






N 




\ 






'_^ii 




1 


\ 




n 


_5fl 




f 






STORE 


•* 


ar 




L 


a 





Table 2. This detailed flowchart is intended to give a better idea of operation of the program. Hex addresses are provided at key 
points. 



102 



played on the KIM display, 
but, instead, we want to use a 
video terminal. You would 
delete both the SCANDS and 
SHIFT LEFT DISPLAY sub- 
routines by removing the 
JSRs and entering NOPs. 
Example: 

Addr e ss Data 



0200 
0201 
0202 
02Clt 
0207 
0209 
02 OB 
020D 
020? 
0211 
0213 
0215 
0217 
021A 
021C 
02JE 
OS20 
0222 

0226 
02 28 
022k 
02ZC 
02 2E 
0230 
0232 

0236 
0238 
0239 
023B 
023c 
023D 
023F 
0241 
02i>3 
D2W 
02^*9 
02'tB 
0240 
02t>F 
0251 
0253 

0255 
0257 

025A 
025C 
025E 
025F 
0261 
0263 
0266 
0268 
0269 
026A 
026c 
026E 
0270 
0272 
0275 
0277 
0279 
027B 
027D 
0280 
0282 
028^ 
028? 
0289 
028C 
028E 
0290 
0292 
029'* 
0296 
0298 
029A 
029D 
029F 
02A1 
02A3 
02A5 
02A? 
02A9 



Before 

0243 20 OE 03 



D8 




58 




A9 


00 


8D 


01 17 


85 


01 


85 


04 


A9 


01 


85 


07 


85 


05 


65 


02 


A9 


80 


85 


00 


AD 


00 17 


29 


80 


C5 


00 


FO 


29 


65 


00 


A5 


02 


PC 


4F 


A5 


03 


PO 


73 


A5 


00 


PO 


11 


A5 


04 


DO 


5A 


A9 


01 


85 


04 


A5 


01 


OA 




85 


05 


i^k 




h& 




85 


06 


A9 


01 


85 


01 


20 


OE 03 


itC 


17 02 


A5 


01 


C9 


7F 


90 


2A 


A9 


00 


85 


02 


A5 


00 


FO 


65 


20 


30 03 


A5 


07 


30 


65 


AA 




B5 


10 


es 


OF 


20 


45 03 


A5 


01 


liA 




EA 




C5 


05 


BO 


5C 


A9 


01 


85 


07 


UC 


3P 02 


A9 


01 


85 


02 


A5 


02 


FO 


C6 


AD 


07 17 


10 


CI 


A9 


Oft 


8a 


07 17 


e6 


01 


tc 


43 02 


A5 


01 


C5 


05 


BO 


23 


G5 


06 


RO 


A9 


A9 


00 


85 


03 


ko 


36 02 


85 


04 


A5 


00 


FO 


30 


A5 


07 



30 98 

A5 01 
C5 05 



0257 20 30 03 


rem( 


After 




SHIi 


0243 EA EA EA 


roul 


Ou code 


02AB 






D2AD 






02 BO 


cw 




02B2 


CLI 




0235 


LDA 


Imm 


0257 


STA 


abs 


0239 


STA 


zp 


02 BC 


STA 


zp 


0232 


LDA 


IniM 


02C0 


STA 


zp 


02C3 


SEA 


zp 


02C5 


STA 


zp 


02C7 


LDA 


Imm 


02CA 


STA 


zp 


02CC 


LDA 


afcs 


02 CE 


ASD 


Imm 


02DO 


CKP 


zp 


02 D3 


BEQ 




02D5 


STA 


2p 


02 07 


LDA 


zp 


02 D9 


BEQ 




02DC 


LDA 


zp 


02 DE 


BES 




02 DF 


LDA 


zp 


02E1 


BEQ 




02E3 


LDA 


zp 


02E6 


Btffi 




02E7 


LDA 


lUM 


02E9 


STA 


zp 


02EA 


LDA 


zp 


02EC 


ASL 


acc 


02EE 


STA 


zp 


02F0 


LSB 


acc 


02P2 


LSR 


acc 


02F3 


STA 


zp 


02F4 


LDA 


imin 


02 P5 


STA 


zp 


02F6 


JaR 


r 


02Pa 


JKP 




02FA 


LDA 


zp 


02 FB 


CKP 


imra 


Q2FC 


3CC 




n2FD 


LDA 


1mm 


02FF 


STA 


zp 


0301 


IDA. 


zp 


0302 


BBS 




n"'>l 


JSS 




0304 


LDA 


zp 


0306 


B^a 




0307 


TAX 




C309 


LDA 


zp.X 


03OB 


STA 


zp 


03OD 


JSE 




03 OE 


LDA 


zp 


0310 


LSR 


acc 


0313 


SO? 


(see article) 


0315 


CKP 


zp 


0317 


BCS 




0319 


LDA 


Inini 


031c 


STA 


zp 


03IF 


JKP 




0321 


LDA 


Imin 


0323 


STA 


zp 


0326 


LDA 


zp 


0328 


BEQ 




0329 


LDA 


ats 


032ft 


BPL 




C32B 


LDA 


Inan 


032D 


STA 


&DS 


032F 


inc 


zp 


0330 


JKP 




0332 


LDA 


zp 


0334 


CMP 


zp 


0336 


BCS 




0338 


CMP 


zp 


033A 


BCS 




033c 


LDA 


iBm 


033E 


STA 


zp 


0340 


JMP 




0342 


STA 


zp 


0344 


LDA 


zp 


0345 


BEQ 




03't7 


LDA 


zp 


034A 


Bill 






LDA 


zp 




CMP 


zp 


END 



0257 EA EA EA 

Here we have effectively 
removed the SCANDS and 
SHIFT LEFT DISPLAY sub- 
>. Since we have 



BC 


2F 




20 


E7 


02 


06 


07 




4C 


3F 


02 


A9 


00 




85 


03 




4C 


3F 


02 


A9 


01 




65 


03 




4C 


3F 


02 


A9 


01 




65 


07 




4C 


5E 


02 


A9, 


00 




85 


07 




85 


01 




4c 


57 


02 


A5 


01 




C5 


05 




90 


OA 




40 


57 


02 


A5 


07 




OA 






09 


01 




S5 


07 




4C 


3F 


02 


EA 






A5 


01 




OA 






85 


09 




C5 


05 




90 


OC 




E5 


05. 




4a 






4a 






4a 






18 






65 


05 




85 


05 




60 






EA 






3S 






A5 


05 




E5 


09 




4a 






l-k 






4A 






S5 


08 




38 






A5 


05 




25 


08 




85 


05 




60 






A9 


7F 




8D 


41 


17 


AO 


09 




A2 


OA 




B5 


00 




6D 


40 


17 


8C 


42 


17 


84 


23 




AQ 


00 




6C 


42 


17 


A4 


23 




C8 






C8 






E8 






EO 


10 




DO 


E8 




60 






A5 


OB 




85 


OA 




A5 


OC 




85 


OB 




A5 


OD 




85 


OC 




A5 


OE 




85 


CD 




A5 


OF 




85 


OE 




60 






A5 


OF 




20 


AO 


IE 


60 







not removed the ADJUST 
SPEED subroutine or the 
OUTCHARACTER routine, 
the resulting program will still 
adjust to new code speeds 
and output the decoded data 
to a terminal. The KIM dis- 
play will not light. !t is pos- 



BCS 
JSB 

ASL Ep 

Jflp 

LDA Ifflai 

STA zp 
JKP 

LIjA Imm 

STA Ep 
J,VP 

LDA Ina: 

STA ZD 
J IIP 

LDA IniDl 

STA Zp 

STA zp 
J«P 

LDA zp 

CMP zp 
BCC 
J«F 

LDA zp 

ASL acc 

OSA Imm 

STA Kp 
JJIP 
HOP 

LDA zp 

ASL aoo 

STA zp 

CMP zp 
BUG 

BBC zp 

LSH aoo 

LSn acc 

LSH occ 
CLC 

ADC zp 

STA zp 
RTS 
NOP 
SiC 

LDA zp 

SBC zp 

LSP. 30C 

W:r'. 3.C.C 

LSH acc 

STA zp 
SEC 

LDA zp 

sac zp 

S1A zp 
RTS 

LDA lnuo 

STA abs 

LDi ImiD 

LDX Ins 

L3A zp.X 

STA abs 
STi'abs 

STY zp 

LDY llEU 

STY abs 

LDjT Imrn 
liff 

i(n 

I NX 

CMX Imr. 
3f)E 
RTS 

LDA zp 

STA zp 

LDA zp 

STA zp 

LDA Zp 

STA zp 

LDA zp 

STA zp 

LDA zp 

STA zp 
HTS 

LDA zp 
JSR 
BT3 



Fig. 4. Program listing. i<ll^~l IVlorse code receive program. 



103 



sibie to run the entire pro- 
gram unchanged, but running 
tine SCANDS without using it 
would waste valuable time; 
running the OUTCHAR^ 
ACTER routine, when you're 
only interested in the KIM 
display, could be a disaster. 
As a good, general rule, re- 
move unwanted subroutines 
with NOPs. Don't waste the 
computer's time; it has been 
given enough to do! 

A few words about the 
heretofore Lmexplained 
SPEED ADJUST subroutine 
— this subroutine, if it has 
not been replaced by NOPs, 
will be called up each time a 
dot is received. The sub- 
routine divides the count 
stored in 0005 by two and 
compares the result with the 
current dot value stored in 
0001. Any difference is 
divided by eight and added 
to, or subtracted from, the 
count in 0005. This new 
value, then, has gradually 
been adjusted to a new code 
speed. Obviously, the 
computer will not accurately 
handle great single jumps in 
code speed but does well with 
substantial changes if they are 
gradual. Without this sub- 
routine, the initial count in 
0005 becomes the dot com- 
parison and cannot change. 
There is, as usual, one catch 
to trying to "cover all 
corners": Occasional bursts 
of static and noise can easily 
fool the subroutine into 
raising the expected code 
speed. In this case, a stJing of 
"Ts" will be displayed. Re- 
initialization is easy, though. 
Hold the initialization 



momentary switch down for 
about a second. The com- 
puter will "start over" in its 
search for code speed. 

Ready to try It? Load the 
program, the character lootc- 
up table ('I'able 1), and begin 
by NOPing the OUTCHAR- 
ACTER subroutine. Connect 
a hand key to the computer, 
as in Fig. 1. Although not a 
major problem, the 0.1 uF 
capacitor across the key 
serves to get rid of some 
switch bounce. Some keys we 
have used worked fine with- 
out it; others seemed to re- 
quire it. Take a look at Fig. 2, 
so you have a little idea of 
what will appear on the KIM 
display once the program is 
up and running after several 
characters. 

Since there is no way to 
display ail letters (let alone 
punctuation!} on a 7-segment 
LED, we have chosen 
symbols that seem easiest to 
identify. Note that an "S" 
must be distinguished from a 
"5", an "O" from a "0", and 
even a "T" from a "1". Once 
you have gotten used to the 
oddballs, you'll recognii^e 
them right away. On a ter- 
minal, of course, you'll get 
standard characters (v/ith the 
exception of ERROR, which 
will print as an "@"). 

If you've gotten this far, 
set up address 0200, and 
press "G". Hold the tape key 
down about a second, then 
simply begin sending. The 
first few characters will pro- 
duce garbage until the com- 
puter determines your 
average dot and dash. Then, 
you'll see proper Morse being 



displayed. You'll soon dis- 
cover how well you're 
sending. Articulate! The com- 
puter and other OiVl will 
appreciate it! Try sending the 
entire alphabet one letter at a 
time. Pause between each and 
you'll see a word space placed 
on the display between your 
letters. This is an ideal way to 
get used to the odd characters 
and to sec which letters you 
don't send very well. 

After becoming thor- 
oughly familiar with the pro- 
gram's operation, you will 
probably want to try it con- 
nected lo a receiver. The 
schematic in Fig. 3 offers one 
suggestion which works 
amazingly well for its low 
cost and simplicity. Connect 
pin 3 of the 567 through the 
.01 capacitor to your head- 
phone jack. Don't forget to 
run a ground from the jack to 
ground on this adapter board. 
The 567 will be looking for a 
frequerTcy of about 2100 Hz. 
This is simply to allow the 
same adapter to work for 
RTTY (we're working on it). 
You won't be able to use a 
CW filter, since this fre- 
quency will be outside its 
bandpass. When you tune in a 
CW signal, flip the "tune" 
switch on. The LED will light"" 
when the 567 hears the 
proper tone. Adjust your re- 
ceiver from the highest fre- 
quency the LED will stilk- 
light with, to the lowest. Set 
your receiver in the middle. 
The circuit is designed to 
have pin 8 ground when it 
decodes the proper tone. The 
567 will thereby simulate 
key-up and key-down for the 



computer. Again, a common 
ground must be shared 
between the adapter and the 
computer. Begin by trying to 
copy a clean-sending station, 
one that is on a fairly open 
frequency, and one that is 
sending moderate speed (13 
wpm is fine). Again, set up 
address 0200 and hit "G", 
and then, after a second or 
so, press the initialization 
momenta^' switch down on 
the adapter board. Let go 
after a second, and the com- 
puter will begin to decode. It 
is advisable to have the 
"tune" switch off after you 
have tuned up. 

Should you be troubled by 
too many word spaces being 
displayed on slow CW, add a 
second LSR to the program 
at 0269. A NOP has been 
placed there as a space filler. 
The Second LSR instruction 
lengthens the time that must 
pass before the computer 
e n ters a word space. 

In retrospect, a program 
this simple (anything that fits 
in less than IK can't be too 
involved) cannot be expected 
to produce perfectly decoded 
Morse. Your initial patience 
will be required until you 
"get the feel" of how the 
computer is accompiishing 
this task. The program is not 
infallible, as it's being re- 
quired to decode a language 
overflowing with variables. It 
does, however, a very respect- 
able job given these condi- 
tions. This is at least another 
step in bringing ham radio 
and computers together; the 
future will be what we make 
it. ■ 



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105 



AJ Gerbens K7SBK 
1033 E. CthPiace 
Mesa AZ 85203 



Build This 
SSTV Pattern Generator 



-- now, if only the FCC... 




The microcomputer. The large box on "the right contains the Digital Group Z-80 system and 
power supply. 



I went directly to pro- 
gramming in BASIC 
after completing the con- 
struction of d Digital Group 
Z-80 system from a kit. i 
postponed machine language 
programming until recently, 
in order to experience the 
games and other slow speed 
applications available in 
BASIC. I've been interested 
in slow scan television for the 
past couple of years, and the 
generation of a slow scan 
video signal appeared to be a 
logical place to get my feet 
wet in machine language pro- 
gramming. The following pro- 
gram is what resulted. I think 
you'll find it interesting. 

Slow Scan Video Signals 

It takes about 7.5 seconds 
to generate a single frame in 
the slow scan format cur- 
rently used by radio ama- 
teurs. Each frame begins im- 
mediateiy following a vertical 
synchronization pulse. This 
pulse consists of a burst of 
1200 Hz oscillations and lasts 
30 milliseconds. This is equiv- 
alent to 36 cycles, with each 
cycle lasting 833 micro- 
seconds. Each frame consists 
of 128 lines, and each line 
starts with a horizontal 
synchronization pulse which 
lasts 5 milliseconds. The fre- 
quency is 1200 Hz, and the 
burstj^ therefore, consists of 6 
cycles, lasting 833 micro- 
seconds each. Following each 
horizontal synchronization 
pulse, there are approx- 
imately 60 milliseconds avail- 
able for the information re- 
quired to generate one of 128 
lines in each frame. The line 
information consists of oscil- 
lations from 1500 Hz to 2300 
Hz, with 1500 Hz rep- 
resenting black and 2300 Hz 
representing white. The line 
data for an intermediate grey 
tone only would, therefore, 
consist of 60 milliseconds of 
1900 Hz oscillations, or 114 
cycles, each 526 micro- 
seconds in length. The fr^ 



106 




Option list showing ttie addition of the seventh option. 



A 3-bar grey scale. 



quency range required to gen- 
erate a slow scan signal is, 
therefore, 1100 Hz, between 
1200 Hz and 2300 Hz. The 
generation of these fre- 
quencies should be well with- 
in the capability of a CPU 
clocked at 2.5 MHz. 

Square Wave Generator 

The first requirement is 
for a machine language sub- 
routine which can generate 
audio frequency oscillations. 
Three possibilities were con- 
sidered : 

1. The program would simply 
generate an 8-bJt word, which 
it would output to one of the 
available output ports. This 
word would be used by ex- 
ternal hardware in the form 
of a digital to analog con- 
verter and a voltage con- 
trolled oscillator, to produce 
a sine wave of the appropriate 
frequency. The pro and con 
are simple software and com- 
plex hardware. 

2. The program would 
generate sine waves using 
only a digital to analog con- 
verter at the output port. 
This would not be a true sine 
wave, but would consist of 
discrete steps of voltage 
changes at the output of the 
D/A. Each step would require 
the outputting of a different 
digital word under software 
control. Using this approach, 
the software is relatively com- 
plex, and an external D/A is 
still required. 

3. The program would 



generate audio frequency 
square waves at the Isb of any 
output port by simply out- 
putting 01 and 00 alternately. 
The advantages are simple 
software, with little or no 
external hardware required. 
The disadvantage is that a 
square wave is generated in- 
stead of a sine wave. If sine 
waves are required, however, 
low pass filter hardware could 
easily filter the high fre- 
quency component of the 
output, yielding a sine wave. 

The latter was chosen be- 
cause most SSTV monitors 
will accept square waves quite 
successfully. The subroutine, 
which generates the square 
wave output, begins at pro- 
gram address 06 78(16) and 
works as follows. 

Prior to calling the sub- 
routine, two numbers are 
entered into registers H and 
L. The number which is 
loaded into register H is a 
timing constant. It will 
determine the length of each 
half cycle and, therefore, the 
frequency of the generated 
square wave. The second 
number, which is entered ir»to 
register L, is the number of 
pulses to be generated. The 
combination of frequency 
and number of oscillations 
defines burst duration and 
function (synchronization 
pulse or line information 
data). The square wave gen- 
erator in the program first 
outputs 01(16) to output 
port one. It then loads the 



timing number, which we 
previously entered into 
register H, into the accumu- 
lator. The timing number is 
then sequentially decre- 
mented with a check for zero 
after each reduction by one. 
On zero, the program jumps 
to memory location 06 
84(16), where a 00(1-6) .is 
outputted to port one. The 
Isb of port one, therefore, 
drops from about (+) 5 volts 
to volts. The same timing 
number from register H is 
then reloaded into the ac- 
cumulator, and the decre- ' 
meniing procedure begins 
again. When the contents of 
the accumulator equal zero, 
one complete cycle has been, 
generated. The number of 
cycles number in register L is 
then decremented by one, 
and a check is made to see if 
it is equal to zero. If it's not 
equal to zero, then another 
cycle is generated by jumping 
back to the top of the sub- 
routine. If the number of 
cycles number is equal to 
zero, then a jump is made to 
the return from subroutine 
statement in memory loca- 
tion 06 99(16). 

The Timing Constant 

Using the square wave gen- 
erator just described, the 
numbers which were loaded 
into register H to determine 
frequency turned out to be 
26(16} for the 1200 Hz 
synchronization pulses and 
22(16) to 16(16) for the 



1 500 to 2300 Hz grey shade 
information. Since 22(16) 
minus 15(16) equals thirteen, 
there are 13 different shades 
of grey which can be gen- 
crated using this system. One 
of the patterns generated by 
this program is a thirteen-bar 
grey scale. 

Program Execution 

Generally, the generation 
of the slow scarh signal takes 
place in the following se- 
quence: 

1 . First a vertical synchroni- 
zation pulse is generated by 
loading 2B(16) into H and 
26(16) into L and then call- 
ing the square wave oscillator 

-subroutine. 

2. Next, the line data sub- 
routine at 06 C6(1 6) is called. 
This routine fiist 
determines which line data 
sequence is to be used, then 
vectors to one of 9 routines. 
Each routine systematically 
loads H and L and calls the 
square wave generator sub- 
routine as many as 13 times 
to generate the information 
for a single line. 

3. A horizontal synchroniza- 
tion pulse is generated by 
loading 2B(16) into H and 
06(16) into L and calling the 
square wave oscillator sub- 
routine. 

4. The line data subroutine at 
06 C6(16) is again called to 
output line data for line 
number 2. 

5. The sequence of horizontal 
synchronization pulse 



107 




A S-targrey scale. 



A 13-bar grey scale. 




A 2 X 2 alternating checkerboard. 



A 4 X 4 checkerboard. 



followed by line data is re- 
peated until 128 lines have 
been generated. 
6. The vertical synchroniza- 
tion pulse is repeated after 
restoring register E to ^28 or 
S0(16), and the next frame 
begins. 

Specifically, I have tised 
the operating system supplied 
with the computer to imple- 
ment the program. The 
operating system consists of 
cassette read, write and dump 
and program routines, in both 
hexadecimal and octal 
number systems. This is a 
good place to relate a feature 
of the Digital Group Oper- 
ating System which is par- 
ticularly valuable in de- 
bugging machine language 
programs. By simply inserting 
an F-7(16) into any memory 
address in the program, you 



can stop the program and 
examine the status of ail 
registers in the CPU, and any 
memory location can be 
examined or altered. When 
the system encounters the 
F7, it stops and displays 
register status, including all 
flag status, and it waits for 
further instructions. I used 
that feature repeatedly in 
developijig this program, and 
it's a tremendous debugging 
tool. 

An addition was easily 
made to the options list, 
which provided a seventh op- 
tion of SSTV, as you can see 
in the photograph. Entering 
seven results in the message 
"HOW MANY BARS" being 
written on the screen. The 
routine which does this uses a 
couple of subroutines located 
in the operating system. As 



you go through the program 
listing, any address less than 
06 00(16) is in the operating 
system. If you adapt this pro- 
gram to another system, these 
subroutines will obviously 
have to be supplied or the call 
and function deleted. The re- 
marks in the listing provide 
function information. The 
slow scan test pattern gen- 
erator portions of the pro- 
gram, however, do not utilize 
the operating system, and, by 
getting the correct number in 
address 06 C5 (16), you can 
select one of nine line data 
routines. The selections avail- 
able are: 

Bl. 4 X 4 checkerboard 

pattern. 

B2. A split screen, with 

black on the left side, 

white on the right side. 

B3. A 3-bar grey scale. 



84. A 4-bar grey scale. 
B5. A 5-bar grey scale. 
B6. A 6-bar grey scale. 
B7. A 7-bar grey scale. 
B8. A 2 X 2 checker- 
board, which alternates 
blatk and white areas 
with each frame. 
B9. A 1 3-bar grey scale. 
All instructions used in the 
program are common to both 
Z^SO and 8080 chips. Instruc- 
tion execution time may be a 
minor problem, if the pro- 
gram is implemented on an 
8080 system. The number of 
grey tones which can be gen- 
erated may be reduced. I have 
it running on a Z-80 system 
with a clock frequency of 2.5 
MHz. 

Results 

The output from the Isb 
port one was connected to 



IC 



the tape input of a Robot 
300 slow to fast scan con- 
verter. The patterns were 
then displayed on a 9-inch 
black and white fast scan 
receiver. The scan converter 
accepted the square waves 
riicely, and, therefore, no 
filtering was iinpiemented. 
The system is capable of r& 
solving the 13 grey tones. 



when displaying the 13-bar 
pattern, and the corners of 
the checkerboard patterns 
line up quite well. The 
vertical lines are reasonably 
straight, and, overall, the gen- 
erator appears to be doing the 
job it was intended to do. 

Conclusion 

Presented is a machine 



■jgram 


listing. 


06 CO 


03 


05 01 


57 


06 02 


06 


05 97 


CD 


06 ?8 


9A 


06 59 


06 


06 5A 


06 


05 JS 


00 


06 5c 


IE 


06 ?D 


80 


06 5E 


26 


06 5F 


2B 


06 60 


2B 


06 61 


26 


06 62 


CD 


06 63 


78 


06 6l^ 


06 


06 65 


CD 


06 66 


C6 


06 67 


06 


05 68 


26 


06 69 


2B 


06 6a 


2E 


06 63 


06 


05 6C 


CD 


06 6D 


78 


06 6E 


06 


06 6? 


73 


06 70 


30 


06 71 


CA 


06 72 


$c 


36 73 


06 


06 7h 


5? 


06 75 


C3 


06 76 


65 


06 77 


06 


06 7S 


3E 


06 79 


01 


06 7A 


03 


06 7B 


01 


06 7C 


7C 


06 7D 


3D 


06 7E 


CA 


06 7F 


?,h 


06 80 


06 



Call subroutirie 

Load B vith 

toad E Kith 12S<10) 

Load H vd-th tine constant for 1200 hz 

Loafi L with 38 (10) = number of cycles foi* 
vertical sync pulse 

Call square vjava eenerator subroistine to 
generate vertical sync pulse 

Gall subroutine to generate line data 

Load K vith 1200 hs freq. constant 

Load L wlti 05 to get 6 cycles of 
1200 hz for horizontal sync pulse 
C-er;er£te horizontal sync. p^iLse 



Load co^l^ents of E into .'iCC-L:i:uX:.tor 
Decrement acc^j::ralator 
Juap on saro to resst nujnber of liii'^a 
petr fraiafr and restart nev frsice 

Lead accumulator into S 

■Tuna to line inforniatlcn subroutine 



Square vave generator subroutine 
Load A with one 
Output to port one 

Load A with rf 

Decrement A 

Jump on zero to generate second 

half of each cycle 



language program which is 
easily adapted to any Z-80 
based microcomputer system. 
The program generates 9 dif- 
ferent slow scan test patterns 
as square wave oscillations 
appearing at the Isb of one of 
the microcomputer's output 
ports. 

Generating these patterns 



using only hardware would be 
a monumental task, while 
producing nuvv patterns with 
a microcomputer is simply a 
mailer of altering a few soft- 
ware instructions. ■ 

Reference 

1. Slow Scan Television Hand- 
book, Don C. Miller W9l\ITP and 
Ralph Taggart WB8DQT, 73 inc., 
1972. 



06 8l C3 

05 82 70 

06 83 06 
06 aV 33 
06 8? 00 
06 86 D3 
06 87 01 

Co B3 70 

06 89 3D 

06 Sa CA 

06 8a 90 

06 8C 06 

06 SD 03 

06 8e 89 

06 8P 06 

06 90 TO 

06 91 3D 

06 92 CA 

06 93 99 

05 9h 06 

06 95 6F 
06 96 C3 
06 97 73 
06 98 06 
06 99 C9 
06 9A 06 
06 9S 05 

05 9C OE 

06 9D B7 
06 9E OA 
06 9? 00 
05 AO CD 
05 A1 ?A 

05 A2 00 

06 A3 CC 
06 A!+ 79 
06 A5 FE 

05 A6 C5 

06 A7 CA 
06 AS AD 
06 A9 06 
06 AA C3 
06 AB 9E 
06 AC 06 



Ju2p back to decren^ent ajain 

Load A vd.th sero 
Output A to part 1 

Load A with H 
Decrement A 
Jump on zero 
to 06 90 

Jump unconditionally to decrenient A 



Load A with L 

Decrement A "'■-., 

Jump on aero to I'etum from call 



Load A with L 

Ju^p to beginnicE of subroutine to 

add another cycle 

Retom frc-n call 
Load B with qq 

Load C with 37 

Load A vith contents of mcTaory location EC 
Call Print Character subroutine vhi ch is 
part of the operating systen; 



Increment C 
Loati A with C 
Compare 

Jump on zero to stop printing 
message 

Jump to continue printine message 



109 



06 HD 


CB 


06 AE 


A8 


06 ^ 


01 


06 BO 


32 


06 B1 


c5 


06 B2 


06 


06 B3 


CD 


06 &t- 


FA 


06 B? 


00 


06 B6 


C9 


06 B7 


C8 


06 B8 


CF 


06 B9 


B7 


06 &A 


01 


06 BB 


CD 


06 BC 


CI 


06 BQ 


CS 


06 BB 


D9 


06 BF 


01 


06 CO 


C2 


06 CI 


C1 


06 C2 


02 


06 C3 


US 


06 Cl4- 


01 


06 C5 




06 06 


3A 


06 C7 


c5 


05 C8 


06 


06 09 


FE 


06 CA 


B2 


06 CE 


CA 


06 CC 


j-s 


06 CD 


05 


05 CE 


FE 


06 CF 


B3 


06 BO 


CA 


06 m 


08 


05 D2 


07 


06 D3 


FE 


06 D<+ 3lf 


06 D5 


CA 


06 D6 


IF 


05 D7 


07 


06 1)8 


FE 


06 09 


B5 


06 DA 


CA 


06 DB 


3C 


06 DC 


07 


06 DD 


F2 


06 D3 


B6 


06 DF 


CA 


06 EO 


60 


06 El 


07 


05 E3 


FB 


06 E3 


B7 


06 El4- 


CA 



CalZ keyooard monitcr routine In 
operating system 

Load input Ir^to address 06 C5 



Call print character subroutine in 
operating system 

Return from call 

H 



V 

Print one blank 

M 

A 

K 

Y 

Print one blank 

E 

A 

R 

E 

Print one blank 

Data; Contains inputted selection 

Load A vd.tb iiiiiaber of bars (contents of 

06 C5) 

Con^pare with 02 

Jump on sero to two bar subroutine 



Compare with 03 



Jump on zero to three bar subroutine 



Compare with 0^ 



Jump on aero to ^ bar subroutine 



Compare with five 



Ju:ip on zero to five bar s\ibroutine 



Compare with 06 



Jump on zero to si:! bar subroutine 



CoEpare with 37 



Jump on zero to 7 ^ar subroutine 



06 EJ 8b. 

06 E6 07 

06 E7 FE 

06 S8 B9 

06 E9 CA 

06 EA BD 

06 EB 07 

06 EC FE 

06 ED 31 

06 EB CA 

06 BP 19 

06 FC 08 

05 F1 FE 

06 F2 b8 
06 F3 CA 
06 F"*^ 63 
06 F5 08 
06 F6 C3 
06 F7 57 
06 f3 06 
06 F9 26 
06 FA 22 
06 FB 2E 
06 FC 2D 
06 FD CD 
06 FH 78 

06 FF 06 

07 00 26 
07 01 16 
07 02 2B 
07 03 ^? 
07 Oh CD 
07 05" 78 
07 06 06 
07 07 C9 
07 08 26 
07 09 22 
07 OA 2B 
07 OB IE 
07 OC CD 
07 OD 78 

07 03 06 

07 OF 26 

07 10 1C 

07 11 00 

07 12 2E 

07 13 26 

07 ^h CD 

07 15 78 

07 16 06 

07 17 26 

07 18 16 

07 19 2B 

07 1 A 2E 

07 IB CD 

07 1C 78 



Compare- «ith 09 



Junip on zero to 13 bar subroutias 



Compare vrith 0' 



Jump on Hero to ^xV checkerboard 



Compare with oS 



Jump on Hero to alternating 2x2 cbeckerboard 



Jump to beginning to regenerate request 
for input 

Beginning of two bar line routine 



Return from 2 bar subroutine 
Begin 3 bar ^ine routine 



110 



07 IB 06 

07 IS C9 

07 IF 26 

07 20 22 

07 21 2E 

07 22 17 

07 23 CD 

07 2h 73 

07 25 06 

07 2& 26 

07 27 IE 

07 28 as 

07 29 1A 

07 2A CD 

07 2B 78 

07 2C 06 

07 2D 26 

07 2B 1A 

07 2? 2B 

07 30 IF 

07 31 CD 

07 32 73 

07 33 06 

0? aif 26 

07 35 16 

07 36 2E 

07 37 23 

07 38 CD 

OV 39 78 

07 3A 06 

07 3B G9 

07 3C 26 

07 3D 22 

07 3S 2E 

07 3F 12 

07 1(0 CD 

07 ^1 78 

07 lf2 06 

07 1+3 26 

07 kh IF 



Return frcm 3 ^^^ subroutine 
Begin V tar line routina 



07 >t5 


2E 


07 


k6 


llf 


07 if7 


CD 


07 


kS 


78 


07 ^ 


06 


07 


IfA 


26 


07 


1(-B 


1C 


07 


he 


2E 


07 to 


17 


07 


te 


CD 


07 


IfF 


78 


07 


50 


06 


07 


51 


26 


07 


52 


19 


07 53 


2E 


07 


5if 


19 



Return 

Begin 5 bar subroutine 



07 55 CD 

07 56 78 

07 57 06 

07 5B 26 

07 59 16 

07 5A 2E 

07 5B 1C 

07 5C CD 

07 5D 78 

07 5E 06 

07 5r C9 

07 60 26 

07 61 22 

07 62 2B 

07 63 16 

07 6k- CD 

07 65 78 

07 66 06 

07 67 26 

07 68 1P 

07 69 2E 

07 6 A 11 

07 6B CD 

07 6C 78 

07 6D 06 

07 6E 26 

07 6r ID 

07 70 2B 

07 71 12 

07 72 CD 

07 73 78 

07 7'+ 06 

07 75 26 

07 76 IB 

07 77 2S 

07 78 ^'+ 

07 79 CD 

07 7A 78 

07 7H 06 

07 7C 26 

07 7D 19 

07 7E 2E 

07 7P 15 

07 80 CD 

07 81 78 

07 82 06 

07 83 26 

07 8>f 16 

07 85 2E 

07 85 17 

07 B7 CD 

07 88 78 

07 89 06 

07 8a eg 

07 8h 26 

07 8c 22 



Eelurn from 5 bar subroutine 
Begin 6 bar line subroutine 



Return rro jp 6 bar line subroutine 
Begin 7 bar line subroutine 



111 



07 8d 


2E 


07 A9 


2B 


1 


07 8e 


OF 


07 AA 


n 




07 8f 


CD 


07 AB 


CD 




07 90 


78 


07 AC 


73 




07 91 


06 


07 AD 


06 




07 9S 


26 


07 A2 


26 




07 93 


20 


07 AF 


18 




07 9'f 


2B 


07 BO 


KE 




07 95 


OC 


07 SI 


U 




07 96 


CD 


07 B2 


CD 




07 97 


78 


07 B3 


78 




07 93 


05 


07 Bk- 


06 




07 99 


26 


07 35 


26 




07 9A 


IB 


07 B6 


16 




07 9B 


2B 


07 B7 


2B 




07 9C 


OF 


07 S8 


1"+ 




07 91) 


CD 


07 B9 


CD 




07 9E 


78 


07 3A 


78 




07 9F 


06 


07 BE 


06 




07 AO 


26 


07 BC 


C9 


Retuin from 7 bar line subroutine 


07 A1 


1C 


07 BD 


26 


Begin 13 bar line subroutine 


07 AJ 


2E 


07 BE 


22 




07 A3 


10 


07 BF 


2E 




07 Alt 


CD 


07 CO 


07 




07 A? 


76 


07 C1 


CD 




07 A6 


06 


07 02 


78 




07 A7 


26 


07 C3 


06 




07 a8 


1A 


07 CH- 


26 





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07 CC 20 

07 CD 2E 

07 CE 08 

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07 DO 78 

07 D1 06 

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07 D7 78 

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07 D9 26 

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07 I5E 73 

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07 E5 78 

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07 E7 26 

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112 



07 FD 19 

07 FE 2E 

07 FF OA 

08 00 CD 
08 01 78 
08 02 06 
08 03 26 
08 Ok- 18 
08 OJ 2E 
08 06 OA 
08 07 CD 
08 08 78 
OS 09 06 
08 OA 26 
08 OB 17 
08 DC 2E 
08 OD OA 
08 OE CD 
08 OF 78 
08 10 06 
08 11 £6 
08 12 16 
08 13 2E 
08 ^i^■ OB 
08 15 CD 
08 16 78 
08 17 06 
08 1 8 C9 
08 19 Ok. 
08 1A 3E 
08 IB 20 
08 1C 90 
08 ID FA 
08 IE 3D 
08 IF 08 
08 20 26 
08 21 22 
08 22 2E 
08 23 17 
08 2h CD 
08 2? 78 
08 26 06 

OS 27 26 

08 28 16 

08 29 2E 

08 2A 23 

08 2E CD 

08 2C 78 

08 ao 06 

09 2E 26 
08 2F 22 
08 30 2E 
08 31 17 
08 32 CD 
OS 33 78 
08 3h 06 



Retxirn from 13 bar line subroutine 

Increment B 

Load 32(10) into A 

Subtract B from A 
Jump on sigs:! negative 



08 35 26 

08 36 16 

08 37 2B 

08 38 23 

08 39 CD 

08 3A 78 

08 3B 06 

08 3C C9 

08 3D 26 

08 3B 16 

08 3F 2E 

08 kO 22 

08 ifl CD 

03 kz 78 

08 11.3 05 

08 kk- 26 

08 li-5 22 

08 1*6 2E 

03 k-7 17 

08 VS CD 

08 V9 78 

08 k-A 06 

08 kB 26 

08 he 16 

08 l+D 2E 

08 ifB 23 

08 M-P CD 

08 50 7S 



08 51 06 

08 Ja 26 

08 53 22 

03 51f 2B 

08 55 17 

08 56 OD 

08 57 78 

08 58 06 

08 59 3E 

08 5a ifO 

OS 5B Bfi 

08 5c CA 

08 5& 60 

08 5B 08 

08 5p C9 

03 60 06 

08 61 00 

08 62 C9 

08 63 01+ 

08 eV 3B 

08 65 kO 

08 66 90 

08 67 FA 

03 68 79 

08 69 08 

08 6A 26 

08 6B 16 

08 6C 2E 



Load &>+(^0') into A 

Compare with B 

Jump on aero to 08 60 to set B to sero 



Return 

Load Kero into B 

Return 

Increment B; Begin 2x2 alternatine board 

Load 6lf(10) into A 

Subtract B from A 

Jtmp on sign negative to 08 79 



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Super 
Baud Bumper 

- for your SWTP 6S00 



I was frustrated by the 
time that was requh'ed to 
load and ptmch 110 baud 
programs on my SWTPC 
6800 computer using an ASR 
33 as an I/O. So I took a long 
look at the alternatives of- 
fered by SWTPC in the com- 
puter documentation. South- 
west had apparently settled 
for a maximum speed of 300 
baud, using Kansas City Stan- 
dard audio cassettes. This 
would aiiow loading a basic 
length program in five min- 
utes, instead of the fifteen 
minutes required at 110 
baud. This would be a signifi- 
cant improvement, but, since 
you're faced with procure- 
ment of additional equipment 
anyway, why not shool for 
something faster? 

A careful review of the 
SWTPC 6800 system revealed 
that baud rates up to 1200 
baud were presently being 
generated in the system and, 



in fact, were bused and clear- 
ly identified on the mother 
board and the CPU board. 
The next step was to settle on 
an I/O for the higher baud 
rate, because the ASR 33 
couldn't hack it. SWTPC's TV 
typewriter, with the optional 
baud rate generator, appeared 
to be the least expensive 
route to obtaining an I/O 
with a 1200 baud capability. 
Then the only bottleneck in 
the system appeared to be the 
serial control interface board 
(MP-C) in the computer, 
which doesn't pick up the 
higher baud rates from the 
mother board. Alas, why did 
SWTPC pass up the opportu- 
nity to provide the user with 
full baud rate control (1 10 to 
1200 baud) throughout the 
system? With the TV termin- 
al, 1 now had 110, ISO, 300, 
600, and 1200 baud capabili- 
ty, with the exception of the 
bottleneck at the serial con- 





CURSOR 


CO^JTROL 






EQUIP 


COfJTRDL 


o 


o 


O 

EL 


■J 


TTV 












\ / 




!;o 


O 


o 

L 


O 

R 


O 

D 


\ / 

TERM 

o 

REACY 


TAP 


OTHER 



Fig. 1 . Panel layout. H - home up cursor to start of page; EL - 
erase screen to end of line; EF = erase screen from cursor 
location on; U = move cursor up; D = move cursor down; L - 
move cursor left; and R - move cursor right. 



trol interface board. 

Investigation of the system 
design and subsequent dis- 
cussions with some of the 
helpful folks at SWTPC indi- 
cated that probably nothing 
would be lost in trying, ex- 
cept the effort. Hoping that 
all advice was sound and that 
I wouldn't smoke the system, 
I began the project. The fol- 
lowing paragraphs outline the 
steps I took and the results 1 
achieved. They are in suffi- 
cient detail to guide anyone 
through the conversion. 

- Step one was to develop -a 
convenient switching system 
to permit: 

1 . Changing of the baud 
rates, at the computer serial 
control interface board and at 
the TV terminal, simulta- 
neously. 

2. Interconnecting the tape 
recorder, the Teletype'T^l, 
the TV terminal, and the 
computer; and 

3. Control of which pieces of 
equipment were on line at 
any given time for maximum 
flexibility in operations. 

To accomplish the modifi- 
cations at minimum dis- 
ruption to the up and going 
system, I decided to provide 
switches on the control panel 
already in use at the TV 
terminal. The control panel 
already provided cursor con- 



trol switching for the ter- 
minal. A neat little two-pole, 
five-position rotary switch 
was procured, which permits 
separate simultaneous switch- 
ing of baud rates at the TV 
terminal and at the serial con- 
trol interface board on the 
computer. Fig. 1 shows the 
panel layout for anyone who 
would like to cold copy what 
has proven to be very 
efficient. The seven momen- 
tary contact push-button 
switches on the left are For 
the cursor controls. 

Space is provided for an 
additional switch or indicator 
at the tower left of the panel, 
if a need should develop later. 
The two-pole, five-position 
rotary baud rate selector 
switch is located in the upper 
center, with a terminal ready 
indicator LED located below 
it. On the right side, six 
single-pole, single-throw 
toggle switches provide selec- 
tive control of the Teletype, 
the TV terminal, and the tape 
recorder. Each peripheral is 
controlled with two single- 
pole, single-throw switches. 
This arrangetjient provides 
split bus control"and permits 
input and/or output selection 
of the peripheral units de- 

.,..sired. A single-pole, double- 
throw is shown in the right- 
hand corner, which controls 
the baud rate selection at 
point C on the serial control 

~ "interface board. Changing 
point C from low to high 
controls the number of stop 
bits at the computer. A sub- 
sequent improvement has 
deleted this control by re- 
placing the two-pole, five- 
position baud rate selector 
switch with a three-pole, 
five-position switch. Wiring of 
the cursor control push- 
button switches is described 
in the TV typewriter docu- 
mentation and won't be ad- 
dressed here. Fig. 2(a} shows 
the wiring diagi'am for the 
two-pole, five-position baud 
rate selector switch and sepa- 
rate single-pole, double-throw 
switch. Fig. 2(b) shows the 
three-pole baud rate selector 
switch, which also automati- 
cally switches the baud rate 
selection at point C on the 



116 



1200 
600 
300 






TO NiOTHER BOARD 



X 



(ZOO 

600 

300 

150 

3=0 

-MOLEX CONN. 



r^ 



TO MOTHER BOARD 



SEftiAL 
CONTROL 
INTERFACE 
eOAffD 



L. 



Fig. 2(a). 



serial control interface board. 

The periplieral unit selec- 
tion switches are straight- 
forward on-off control of the 
input and output of the 
RS232 data to and from the 
units. A wiring diagram for 
the switching is shown in Fig. 
3. Additional peripheral de- 
vices can be controlled by 
additional pairs of switches 
on the control panel. 

The actual connections 
that were made to the com- 
puter arid the terminal will be 
described for those who may 
be hesitant to experiment, A 
step by step test out will also 
be described. The only draw- 
back is the additional wiring 
that runs from the computer 
and the terminal to the 
switches. A neat installation 
can be had with average care. 

Step 1. Locate a con- 
venient place for the control 
panel. A word of caution: 
Limit the length of the wires 
from the baud rate selector 
switch to the computer to an 
absolute minimum. You are 
dealing with digital devices, 
and long leads leaving printed 
circuit boards invite prob- 
lems. ! experienced none, but 
the possibility always exists. 

Step 2. Lay out the 
switching control that best 
suits your needs. The panel 
layout in Fig. 1 can be used, 
if it suits you, or you can 
come up with your own. 
There is nothing critical in 
the layout, only convenience. 
IVlount the switches in the 



control panel. 

Step 3. Solder one set of 
leads on the baud rate selec- 
tor switch, SI a. It's suggested 
that you color code the leads 
for troubleshooting con- 
venience. Five leads go from 
switch SI a directly to JS-I on 
the serial interface or UART 
board of the TV typewriter. 
Connections are shown in 
Table 1. A sixth lead from 
the wiper of the switch goes 
to ground, because grounding 
activates the baud rate se- 
lected by the switch. See Fig. 
2(a) or 2(bJ, depending on 
which switching arrangement 
you used. 

Step 4. Solder the second 
set of leads on the second 
pole of the baud rate selector 
switch. Sib, using the same 
color code as used in Step 3. 
Solder a female molex con- 
nector, that matches the pins 
on the mother board, to the 
computer end of these leads. 
This connector can be plugged 
onto any vacant set of 
piris from the baud rate buses 
on the mother board. The 
molex connector is available 
from Southwest Technical 
Products Company, if you 
can't find it locally. The sixth 
lead from the wiper of the 
second pole of the baud rate 
selector switch. Sib, goes to 
point "D" on the serial con- 
trol interface board of the 
SWTPC 6800. There are no 
connections to "110" and 
"300" adjacent to point "D" 
on the serial control interface 



in. 



i 



£5 \ S6 



JH 






SWTPC 6300 



^— TO COMPUTER 
-FROM COMPUTER 



^ 



■/--: 



- 1200 
-GDO 

-300 



'-MOLEX CONN. 



Sic I 



r" 



SERIAL 

COMTROL 

INTERFACE 

BOARD 



I 

Fig. 2(b). Note t/iat switch S2 is not used in t/iis scheme. 



Fig. 3. 



board. Be sure to remove any 
jumpers you may have in- 
stalled at these points. These 
two sets of leads should be 
bundled or six-conductor 
cable should be used, to pro- 
vide a neat installation. See 
Fig. 2(a) or 2(b). 

Step 5. From switch S2 in 
Fig. 2(a), connect three wires 
to the switch. These wires ail 
go from switch S2 on the 
control panel to the serial 
control interface board of the 
computer, so consider bun- 
dling them with wires in step 
4 for neatness. The center pin 
of the switch is connected to 
point "C". The 100 baud 
speed side of the switch goes 
to "110" adjacent to point 
"C", and the "other" side of 
the switch provides all other 
baud rates and is connected 
to "300" adjacent to poinf 
"C" of the serial control 
interface board. 

Step 6. Connect the com- 
puter side of switches S3, SS 
and S7 together. This forms 
the "output from computer" 
bus. Connect the computer 
side of switches S4, S6 and 
S8 together. This forms the 
"input to computer" bus. 
You have now established 
common input and output 
buses for the computer. Con- 
nect switch S3 to the input 
side and switch S4 to the 
output side of the TV termi- 
nal (TVT). Connect switches 
S5 to the input side and S6 to 
the output side of the tape 
recorder (TAP). Connect 
switches S7 to the input side 
and S8 to the output side of 
the Teletype (TTY). The 
grounds for all peripheral 
devices and the computer are 
connected together, as shown 
by line G in Fig. 3. 

Step 7. If you want the 



terminal ready LED, connect 
the anode of the LED to the 
terminal ready connection, 
which is pin 2 of JS-1 on the 
TV terminal. The cathode of 
the LED should be grounded 
through a 250f2, 14 Watt resis- 
tor. The terminal ready line is 
limited to sensing and to a 5 
mA current, so don't forget 
the resistor. 

Now, if you have carefully 
checked your connections, 
you are ready to check out 
your conversion job. At this 
point, you probably have 
abandoned the step by step 

. procedure and have changed 
things around to suit yourself 
and that's fine. 1 did, too, 
renaember! Butj-for the more 
timid, 1 will go ahead with a 
checkout procedure. These 
tests assume that you have 

•the optional baud rate genera- 
tor in your TV terminal and 
that you have a digital tape 
recorder (or. have 'Borrowed 

..one). The tests don't have to 
be performed in any particu- 
lar order. Depending on the 
peripherals you have connect- 
ed, the checkout must be 
arranged to suit your condi- 
tions. 

In all cases, the input to 
computer srde of the RS232 
connections from the periph- 
erals should show a negative 
voltage when the peripheral is 
switched on. Check each one 
individually at the input to 
computer bus to assure 
proper connection. If you 
don't get a negative volt- 



Baud 


rate 


JS-1 




110 




pin no. 


9 


150 




pin no. 


10 


300 




pin no. 


11 


600 




pin no. 


12 


1200 




pin no. 


3 



Table 1. 



117 



age, try reversing the leads 
from the peripheral you are 
testing. 

Test 1. Open switches S3, 
S4, S5 and S6. Close switches 
S7 and S8. Set baud selector 
switch to 110 baud. Set 
switch S2 to "110". This 
arrangement connects only 
the Teletype to the com- 
puter. Test your MikbugTM 
memory address functions — 
they should work normally. 
If they don't, you have prob- 
ably reversed the leads from 
the Teletype to S7 and 58, so 
try reversing them. If you are 
satisfied at this point, load a 
machine language program 
such as tic-tac-toe or black- 
jack into the computer via 
the paper tape reader on the 
Teletype. Open switches S5, 
S6, S7 and S8. Close switches 
S3 and S4. Set switch S2 to 
"OTHER." Set baud selector 
to 1200 baud. Type in "S9" 
and "G" on the TV terminal, 
and the program should be 
initiated at 1 200 baud. Check 
the remaining baud rates, 600 
to 150, on the TV terminal. 



Change S2 to "110", and 
check the 110 baud rale out 
If this step has checked out, 
go to test 2. About the only 
problem you would en- 
counter is reversal of leads 
from switches S5 and S6 to 
the tape recorder. 

Test 2. Open switches S5, 
S7 and S8. Close switdies S3, 
S4 and S6. Set baud rate 
selector switch to 1200 baud. 
Set switch S2 to "OTHER." 
This arrangement connects 
the "from computer" side of 
the tape recorder and the TV 
terminal to the computer, 
and it sets up for a print- 
punch operation, which will 
transfer the progiam resident 
in the computer to the tape 
recorder. After you have the 
program dumped to tape, 
turn the computer off to 
clear the program from mem- 
ory. Power the computer 
back up. Using the TV ter- 
minal at 1 200 baud, type " L" 
to initiate the progi'am load 
function. Open switches S3, 
S4, S5, 57 and S8. Close 
switch S6. Load the program 



from tape into the computer. 
Open switches S5, S6, S7 and 
S8. Close switches S3 and S4. 
Initiate the program at 1200 
baud by typing "S9" and 
"G". Go through the above 
listed procedures for baud 
rates of 150 through 600. 
Then set SI and S2 to "110", 
and check out the 110 baud 
rate for dumping and loading 
of programs. 

Test 3. If steps 1 and 2 
were successful, let's proceed. 
So far we have checked out 
the Teletype, the TV termi- 
nal, and the tape recorder, 
individually. Now it's time to 
try split bus operation. Set 
the baud rate selector switch 
and switch S2 to 110 baud. 

Open switches S4, S5 and 
S6. Close switches S3, S7 and 
S8. We now should be able to 
input data from the Teletype 
keyboard and output data on 
the Teletype and TV termi- 
nal, simultaneously. Try itand 
see. This will only work at 
110 baud, because that's the 
limiting speed of the Tele- 
type. E.xperiment with the 



other functions. 

There are obviously other 
tests you could run, but, if 
tests 1 through 3 were okay, 
you should now have a sys- 
tem that has reduced load 
and print-punch time by a 
factor of 12, if you were 
using 110 baud, and by a 
factor of 4, if you were using 
300 baud. Quite an improve- 
ment, wouldn't you say? We 
set out to provide faster load- 
ing of the SWTPC 6800, and 
we succeeded! 

Once again, if you are 
reasonably careful you prob- 
ably will have no problems. 
Too long leads from the baud 
rate switch to the computer 
could cause problems, but 
check for wiring errors, 
switch setup errors, and/or 
reversed wiring before you 
blame lead length. I hope this 
gives others as much fun as 
it's given us. I would like to 
see what control panel and 
switching arrangements you 
come up with, so how about 
dropping me a line and send- 
ing me a picture? ■ 




ns 



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TELETYPE^ MODEL 33 ASR 



COMPUTER I/O COMPLETE WITH 

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TAPE SPINDLE (182918) $1.25 
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23 ROLLS 1 CARTON $32.00 
7 ROLLS 1 BOX $10.00 
MYLAR 1 ROLL $23.00 

REPERF COVERS (132109) $3.50 
RepiacBment UPE-SOO PUNCH S75.00 
CHAD BOX (1829B5) $3.60 
Replacement UX30O READER $50.00 
REPAINTED STAND WITH FEET — 
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FEET ALONE (183243) $12.0D/Pr. 
LINE CORD (132510) $3.25 




PAPER -WHITE or CANARY 
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SINGLESPODL$ll/Doz. 
DOUBLE SP00L$15/Doz. 
•ANSWER BACK DRUM (180827) $7.00 
CODED (SPECIFY CODE) $10.00 
DOME LID (181137) $5.75* 
BLANK PLATE (181910) $7.00* 
KNOB (181824) $1.00 
KEYTOPS (YOUR CHOICE) 60c Ba. 
ONE PIECE COVER (187300) $22.00* 
UCC-6 LINE-LOCAL $150.00 
UCC-3F0RTWX $150.00 
FRONT PLATE (181812) $2.50 
DATA SETS 101 C FOR TWX $450.00 
NEW 105A FOR TWX $300.00 



COMPLETE COVER READYTO INSTALL 

INCLUDING ALL *'s % 36.00 

COPY HOLDER (182035) $ 14.00 

TAPE UNWIWDER (12") £ 32.0D 

WIND UP PAPER TAPE WINDER % 22.00 

ELECTRIC TAPE WIMDER S 65.00 

ELECTRIC PAPER WINDER (LPW-SOO) ... $ 50.DO 

DEC TYPE READER RUNCARD $ 45.00 

ACOUSTIC COUPLER 

OIMNITEK 701A $160.00 

READER POWER PACK (182134) $ 35.00 

STANDARD EIA !(\ITERFACE $ 55.00 

ACOUSTIC COVERS with FAN $258.00 



If YOU don't see what you need, CALL or WRITE! O W its for TELETYPE® We Have It. 




TELETYPEWRITER COMMUNICATIONS SPECIALISTS 

550 Springfield Avenue • Berkeiev Heiglits, Hi. J. 07922 

{201)464-5310 • TWX: 710-986-3016 • TELEX: 13-6479 

Deaf LineTTY: 201-464-5314 

SUBSIDIARY OF VAhIT SLOT ENTERPRISES, mC. 



PLEASE NOTE 
Due to increased costs of processing orders min- 
imum orders: $10.00 casli or check, $25.00 charge. 
All orders sliipped UPS. Please include sufficient 
postage. T13 




119 



QRZ -- P-K4! 



-- relax with ham chess 



Russell C. Parker VJ9CQD 
781 4 Keeler 
Skokie IL 60076 



Avid chess players will 
recognize P-K4 as the 
opening Bobby Fischer uses 
m the majority of his chess 
games. What's your favorite, 
and have you tried it on ham 
radio? There is plenty of 



radio chess going on in the 
ham bands. If you like chess, 
why not join in? You don't 
have to be an expert, you just 
have to like the game. Com- 
bining two interests makes 
them even more enjoyable. 

OK, you say, I like chess. 
Where can I find a game on 
the radio? First of all, here 
are some frequencies where 
chess players can be found; 



Midcars, 7258 kHz; Eastcars, 
7255 kHz; and Westcars, 
7255 kHz are service groups 
which operate most of the 
daylight hours. Check in and 
ask if any chess players are on 
the frequency. When you 
make contact arrange to QSY 
and start your game. If you 
don't make contact ask the 
service control to list your 
request or just monitor for a 




Rus W9CQD playing radio chess. 



while until someone else 
checks in and asks for a chess 
game. 

Another frequency to 
monitor, starting about noon, 
is 7235 kHz. There is a pretty 
regular group on every day, 
and they will welcome some 
fresh talent. Evenings, after 7 
pm, try around 3990 kHz and 
3928 kHz for two other 
informal, friendly gatherings. 

Now for some tips on 
beating the dipoles for op- 
ponents on your own. Firstly, 
bring up the subject during 
your usual QSOs. It's surpris- 
ing how many hams you will 
find who know how to play 
and might be interested in a 
game. If they don't have time 
immediately, try to arrange a 
schedule. Check in any traffic 
net, and make a request for 
chess players. Always move 
off frequency quickly. Decide 
beforehand where you want 
to move so you will not hold 
up the net. Contact any local 
amateur radio club. Leave 
your phone number with the 
officers, and ask them to 
inquire of their membership 
whether anyone would like to 
set up a scheduTe. Put out a 
call on 2 meter FM repeaters. 
Again, always arrange to QSY 
quickly when you make con- 
tact with a player. Ask your 
opponents if they know of 
anyone else interested in 
playing radio chess. Keep at 
it, and soon you'll have a 
good list to choose from. 

Now for some hints about 
actual play, it may be a little 
hard to maintain concentra- 
tion*- because of noise or 
QRM. Remember, this is for 
fun, so enjoy it and don't fret 
about losing a game or two. 
You'll find a great variety of 
skill in the various chal- 
lengers, so if you are up 
against an excellent player, 
don't prolong a game when 
you are down one or more 
pieces. Resign and start over 
rather than try to make him 
mate you. He's more apt to 
.be willing to play you again. 

Always score the game, 
that is, write down the 
moves. This helps if you have 
a mix-up and want to 
straighten out the board. Say 



120 



your moves twice and always 
acknowiedge the other fel- 
low's moves. In radio chess 
you have the opportunity to 
move the pieces around to see 
how a particular position 
looks, and it is easy to forget 
to move a piece back to the 
right square. Try to avoid this 
if you can. You certainly 
would not be allowed to do it 
if you were playing across the 
board. It becomes a bad habit 
as well as leading to messing 
up the board. 

Don't be afraid to play 



because you don't know 
chess notation. It can be 
learned in a few minutes. Ask 
an experienced player to 
explain it or check any ele- 
mentary chess book at your 
local library. Try not to talk 
to your opponent while he is 
contemplating his move. 
Sometimes it helps to keep 
the frequency clear if two or 
three games are going on at 
the same time. It may be a 
little hectic at the beginning, 
but after the moves start 
slowing down, you'll be able 



to maintain the frequency 
since someone will be making 
a move more frequently than 
if only two were playing, and 
it won't seem fike the fre- 
quency is clear. Explain to 
polite hams who ask if the 
frequency is in use that you 
are playing chess and are 
quiet between moves. 

Don't rule out CW for 
your games. They can be just 
as rewarding as phone. Also, 
look out for the ladies. They 
play, too, and some are excel- 
lent players. 



When you get established, 
why not go for PAS — Played 
Ali States? DX hounds will 
find overseas players, though 
the bands may not hold up 
for the length of the game. 
You may want to adjourn a 
lengthy game and finish 
another day, another reason 
to write down the moves. No 
reason not to try SSTV or 
RTTY either. 

And who knows? When 
you get a winning streak 
going, try for a phone patch 
to Bobby Fischer. ■ 



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•5f 



You asked for it! 
A $70.00 digital multimeter kit 

Now there's just no excuse for not 
having a digital multimeter at our low 
price. Our unit is based on the famous 
$29.95 DVM kit you have heard about 
and has the following features: 

DC volts: Better than 0.1% ac- 
curacy. Reads to 1200 volts in 4 
ranges 

AC volts: Better than 0.3% ac- 
curacy. Reads to 750 volts 
RIVIS/4 ranges 

Ohms: Better than 0.2% accuracy. 
Reads from ohms to 20 rrtegs 
You get all parts including dual tracking, 
AC power supply, laser trimmed reference, 
and thick film attenuator. 

CA re^. add tax. Pis. inc. $3.95 for postage 
handling. 

/4j- always Mr h^vf^ i:ahbyiiUon and y^paiy i^crvia; 



Gary McClellan and Co. Box 2085 

n'i^ 1001 W. Imperial Hwy. 

La Habra CA 90631 



Don't Buy an Anqplif ier on 
Toothpaste Claims 




Buy a tube of toothpaste on the basis of outrageous exaggerations as 
to what it'll do for your social life and it still may clean your teeth. 

BUT if you buy a linear amplifier on the basis of toothpaste claims — or 
ambiguous specifications — you may end up with a real turkey! .. .. 



Large differences in quatity and pEJ-fomsarice ex:3t among 
so-called "2 KW PEP amj^lifjers Thinking oS buying 
ajiodier iTiodel !l^af 3 "just as good as an ALPHA'' Better 
tlioroughly mvesugaie Iha manufacturer s reputation 
and wnat, exacHy, --^ promised in tiis specifications and 
warranty Unless, of course, ^ou liKe surpii£es. 

EXAMPLE — Power Output & Efficiency; 

An ALPHA 76 running Key-down at one-'kilowati DC inpjt 
deli*/ers well over 600 watts rf ouipul, averaged Over Jhe 
loDiftru 10 meler amateur bsr^cis Another current model 
"'del uxe" iinear managed less ihan JOO watts average out- 
put in identical tests using Itie same instrumentation. Vou d 
newer suspect it from reading thie msnulacturcr s claims 



and specs. ^ arisl :he deficrency was largely conce^'ed iyf 
gross errors m \ht> iniema? meteung circuits' 

EXAMPLE — Duty Cycle: 

Ratings are somstirnea ambigyatJS and can be mislesdin^ 
One prominent amplifier manufacturer rales HiS desk 
model for full powei in intermittenl amatsur service [Just 
how iriiernnitieni fie doesn t say.y Another manutsciurer 
hedges fiis ' coniinuoos ratine with time limits for one 
fnodeJ. but nol lor a ser.nnd model. 

ALPHA specs say clearly. ' ifc Time Limi1 " And EvGry 
ALPHA rs backed by a faciory uvanranly itiat extends IS 
manihs — sk times ^s long as other ^mplilisr warranties' 




It's understandable v/hy certain Of our competitors hi 
Ihe ALPHA 76s !oriy-(ive pound irai^sformer alone welgtis 
as mucfi as some of ttie complete linears for wti;cti ihey 
claim capatiility r?qua1 lo tne 76's And every ALPHA power 
transformer is efficiently cooled tiy ETO's exclusive dueled 
air system. You owe il to your&elL before buying, to check 
liow (if at all) the smaller transfoj^mers in ttiose otlier 
desk-iop linears are cooled 



To get the tacts about what an ALPHA linear ampMier can 
do in your station, call or v^nie your dealer or ETO direct Inr 
detailed hlerature And asH for a tree copy of our newly- 
updated guide to comparing lincarS 



ALPHA: Sure you car buy a cheaper linear, . 
that reaiiy what you want? 



K fB Ehrhorn Technological Operations, inc. 

P,Obox708 ■ CinonCiEv. Colorado Hi2l2 ■ C-ldS) 275-l6l:'^ 



121 



Digital Timer 



Goes Mobile 



- - battery power keeps it trucking ! 



Frank W. Kiio;:inghan! K7QCM 

P.O. Box 734 

Gold Beach OR 97444 



Having built the frequen- 
cy counter written up 
by Thomas Harper and pub- 
lished in the August '73 issue 
of 73 Magazine, three alarm 
clocks from the 50250 chip 
outward and five of the 5314 




kits, 1 was captivated by the 
flying numbers, and it was 
easy to convince myself that i 
needed a time period counter 
in my service truck. 

So I built up out of 7400 
series ICs a 3 digit timer to 
count the time I was on a 
service cali. This worked 
quite well until the engine of 
the truck was started during 
the counting period. Then the 
readouts wouid maybe show 
correct time interval or 

Photo by Wally Blackburn K7SEG 

\ 



maybe not. So back to the 
old think tank and, lo, the 
perfect interval counter was 
born. 

An order was sent off to 
S.D. Sales for their current 
clock kit using a 50250 chip 
and a 60 Hz CMOS timebase, 
which was the one being ad- 
vertised at the time. The two 
kits were assembled and 
mounted in a small 10^4 cm" 
wide by 4 cm high by 1 1 cm 
long metal box hinged to a 





W \"-ti.mi„mi~ 



base at the lower rear corners. 
Two switches were installed 
in the bottom of the box. A 
push-button switch as used in 
a table lamp turned the 12 
volts from the car battery on 
and off at a touch of the top 
of the metal box. At the same 
time a microswitch made up 
of two miniature micros fas- 
tened together and operated 
by a common push-button 
ser\'ed to momentarily con- 
ned the hours-set and 
minute-set pins of the clock 
chip lo the positive supply 
voltage which then wouid 
start the seconds counting. 
This interval timer has been 
in use for a couple months 
now and has not been caught 
giving a false reading. 

When power is inter- 
[xipied, a 50250 clock chip 
will return to either 12:00:00 
or all zeros, depending on 
whether it is used as 12 hour 
time with a 60 Hz timebase 
or 24 hour time with a 50 Hz 
timebase. Some day I will get 
a CMOS 50 Hz timebase and 
go for the 24 hour format. At 
the present, starting at 
12:00:00 is. a bit awkward, 
especially arouiid noon time. 

Why didn't the original 
timer work? My best guess is 
that since the 7400 scries ICs 
needed 5 volts, which were 
obtained through a 309 regu- 
lator IC which.-requires at 
least 1 volts for stable regu- 
lation, then probably the 
starter pulled the voltage 
down to or near this point 
and caused the confusion. 

The clock chip and time- 
base-use 12 volt supply direct 
and are quite tolerant of low 
voltage. 

A cabinet to house a pro- 
ject such as this always pre- 
sents as much problem as the 
circuitry, to me at least. What 
really took place there was 
that during the first lash-up 
•and test period I found a box 
made of thin cardboard that 
just tit the circuit boards. The 
timebase was wrapped in 
crumpled newspaper and 
shoved down in this card- 
board box. Then came the 
main circuit board with the 
clock chip on it, and the 
readout board was last with 



122 



the readout board plugging 
the whole box top and the 
switches dangling. This lash- 
up was tied to the steering 
post and put through the 
smoke test in this unfinished 
condition. When it looked 
like everything would work, a 
metal box was made to just 
cover the cardboard box; a 
hole drilled through this 
received the push-push power 
switch, which in turn held the 
works in the metal box. An- 
other hole permitted the 
power wires to be led out and 



the two microswitches to be 
wired outside of the box. 

The choice of switches is a 
determining factor in the 
placement of the micro- 
switches and the lever arrange- 
ment. In this case the two 
microswitches were lightly 
hinged to the box by putting 
smail screws in the plate of 
the switch pair and the 
push-buttons of the switches 
up against the box. The wires 
are stiff enough to provide 
the necessary force to close 
the switches. If the larger 



microswitches requiring more 
force to trip them were used, 
it would be necessary to pro- 
vide a spring to supply this 
force, as a push -push switch 
needs an overrun on the 
stroke to trip it. The hours 
and minutes switch can be 
closed first, but has to give 
down enough for the 
push-push switch to turn the 
power on. 

The current available 
50250 clock chip seems to 
have turned into a 50252, 
possibly an updated version. 



There may be other clock 
chips which will work, but 
remember the requirement: 
The readouts must go to zero 
when the power switch is 
opened and closed again. 
Many of the clock chips will 
show some random number 
which, of course, is unsatis- 
factory. 

A one finger push down 
toward the base will start this 
timer counting the seconds, 
and another push will turn 
the whole thing off 
a^in. * 



ATTENTION GARY AND SABTRONIX 
OWNERS! 

. . . .Come let us tweak your 
pots! If you just built the Gary 
Model 101 or the Sabtronix model 
2000 we can calibrate it for you to 
factory specs. 

We use custom built lab calibra- 
tion equipment designed expressly 
for these meters. You get a profes- 
sional job! 

Sabtronix 2000 $24.95 
Gary model 101 $10.95 

Also add $3.95 per unit for 
special delicate equiptTient packing, 
insurance, and postage. 
Send via Air Mail or Parcel Post to: 

custom cal service 



GIO 



Gary McClellan and Co. 
PO Box 2085 
1001 m. Imperial Hwy. 
La Habra CA 90631 



PRINTED CIRCUIT 
SUPPLIES 

Do a PC layout using onty a 
drill press and a set of 
Stabler Drill/Mills. You can 
also do a prototype using 
Datak ER-2, ER-13, ER-14 
tape resist. Positive resist 
permits identical reproduc- 
tions from an artwork layout 
on matte film. 

PC Techniques Booklet, 
Positive Resist instructions, 
and catalog: $1.50 

TRUMBULL COMPANY 

833 Baira Dr., El Cerrito, CA 94530 




The HAL ST -5000 sets the pace for an economiccd 
demodulator/keycr for radio-teletype (RTTY). All the fea- 
tures you need for reception and transmission of HF and 
VHF R r lY are here. 

The demodulator features a hard-limiting front end,^ 
active filter discriminator, and active detector circuitry for 
wide dynamic range. Autostart and motor control circuitry 
make for easy VHF and HF autostart operation. 

Convenient front [lanel switches are provided for 850 
and 170 Hz shift, normal or reverse sense, autostart on/off, 
print - line or local, and power on/off. 425 Hz press 
transmissions may also be copied with the SJ-5000. High 
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The audio keyer section of the ST -5000 generates 
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VHF FM transmitter. 

The ST-5000 is housed in an attractive blue and beige 
cabinet and is backed by the HAL Communications one 
year warranty. 

For complete specs on the HAL ST-5000, write or call 
HAL today. $275.00 



ffl 



HAL Communications Corp., Box 365, 807 E. Green St. 
Urbana, Illinois 61801 • Telephone (217) 367-7373 



H6 



123 




YD-844 
Dynamic Mike 



Y/A 





yj 



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I 




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IM MOBILE/BASE FM TRANSCEIVER. Ignition 
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$145.00 



Designed exclusively for use with TS-820. RIT 
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VFO-520 (Not Shown) S1 1 B.OB 

Solid Slate Remote VFO. RIT circuit with LED 
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COMMUNICATIONS RECEIVER. 1.8 to 29.7 
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TR-2200A 



$229.00 



PORTABLE 2M FM TRANSCEIVER. 12 Ch. 

caoacity. Removable telescopiog antenna. External 
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R-30a 



S239.00 



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AC, batteries or external DC. 170 KHz to 30 MH^ 
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marker. 



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SPR-4 Programmable, Solid State 

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41MB Noise Blanker for R-4C 

5NB Noise Blanker for SPR-4 

TRANSMITTER 

T4XC C-Line. HF. 160-1 CM 



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$2950.00 

$599.00 

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$599.00 



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TR-4CW 


80-10M.SSB, AM, CW 




$699.00 


TR-33C 


2M, FM, 12CH. Portable 




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IVlMK-33 


Mobile/Dash/Desk Mount for 


TR- 






330 




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Plug-In Noise Blanker for 


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Mobile Mount for TR-4 




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Remote VFO for TR-4CW 




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FF-1 


Crystal Control for TR-4 




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General Coverage for 4-Line 


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LINEAR AMPLIFIER 

L-4B Linear and w/power supply & tubes 

MATCHING NETWORKS 



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MN-4 


Antenna Matching IMet work. 200W 


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MN-2000 


Antenna Matching Network. 1000W 


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RGS4 


Remote Control Antenna Switch 


$120.00 


W-4 


RF Wattmeter, 1.8 to 54 MHz 


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WV-4 


RF Wattmeter, 20 to 200 MHz 


S84.00 


7072 


Hand Held Microphone 


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7075 


Desk Top Microphone 


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1525EM 


Pushbutton Encoding Microphone 


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HS-1 


Head Phones 


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AA-10 


low, 2M Amplifier 


$49.95 


TV-300-HP 


300 ohm High Pass TV Set Filter 


$10.60 


TV-75-HP 


75 ohm High Pass TV Set Filter 


$13.25 


TV-42-LP 


Transmitter Low Pass Filter. 100W 


$14.60 


TV-3300-LP 


Transmitter Low Pass Filter. 1000W 


$26.60 


TV-5200-LP 


Transmitter Low Pass Filter. 1000W. 






100W, 6M 


$26.60 



USED GEAR • TRADE UP • FREE UPS SHIPPING ON PREPAID ORDERS 



■mEmniMn 



COLLINS AMATEUR EQUIPMENT 




"^m 



#?^- 



KWIVI-2A TRANSCEIVER S3533.00 

Unmatclied for mobile and fixed station applications. 175W 
on SSB, 160W on CW. Switch select up to 14 optional Xtals. 
Can be used for BTTY, Filter type SSB generation. Automatic 
load control. Inverse RF feedback. Reimeabilitytuned variable 
oscillator. 




75S-3C RECEIVER $2504.00 

Sharp selectivity- SSB, CW and RTTY. Single control rejection 
tuning. Variable BFO. Optional mechanical filters for CW, 
RTTY and AM. 2.1 KHz mechanical filter. Zener regulated 
oscillators. 3position AGC. 



X 

o 




32S-3A TRANSMITTER $2597.00 

Covers all ham bands between 3.4 MHz and 30 MHz. Nominal 
output of 100W. 175W, SSB and 160W CW. Dual conversion. 
Automatic load control. RF inverse feedback. CW spotting 
control. Collins mechanical filter. 




312B-3 SPEAKER 
$80.00 








30L-1 LINEAR AMPLIFIER - .. S1536.00 

1000 watts PEP on SSB and 1000 Average on CW. Single con- 
trol rejection tuning (SO dB). Variable BFO, 2.1 kHz 
Mechanical filter. Zener regulated oscillators. 3 position AGG. 
Exciulsive comparator circuit. 




■ 312B-4 

SPEAKER CONSOLE 
$544.00 




516F-2 AC POWER SUPPLY 
$440.00 



302C-3 DIRECTIONAL WATT METER 
$360.00 




" vli^— 



312B-5 VFO CONSOLE 
$1212.00 




DL-1 DUMMY LOAD 
$270.00 



MASTERCHARGE & BANKAMERICARD ACCEPTED 



wTTR? 



DIVISION OF TREVOSE ELECTRONICS 

4033 Brownsville Rd • Trevose, Pa. 19047 
(215) 357-1400/(215) 757-5300 



(9 

I 




BUY ONLY THE ELEMENTS YOU NEED 
AND ADD EXTRA RANGES AT ANY TIME 

READ RF WATTS DIRECTLY 



MODEL 43 





Power 
Range 






Frequency Bands (MHz) 




Table 1 


2- 
30 


25- 
60 


50- 
125 


100- 
250 


200- 
300 


400- 

1000 


STANDARD 


5 watts 


_ 


5A 


5B 


5C 


5D 


5E 


ELEMENTS 


10 wans 


— 


lOA 


10B 


TOC 


10D 


10E 




25 watts 


-^ 


25A 


25 B 


25C 


25D 


25E 




50 vvatt5 


50H 


50A 


50B 


50C 


50D 


50E 




100 watts 


100H 


100A 


100B 


100C 


lOOD 


100E 




250 watts 


250H 


250A 


250B 


250C 


250D 


250E 




500 watts 


500H 


50aA 


500B 


SOOC 


500D 


500E 




10»0 waits 


1000H 


1000A 


1000B 


1000C 


1000D 


lOOtK 




2500 watts 


250OH 














SOOO watts 


5000H 













Table 2 

LOW- 
POWER 
ELEMENTS 



WE HAVE A COMPLETE STOCK OF ALL BIRD WATTMETERS AND SLUGS 



1 wall 


Cat. No. 


2.5 walls 


Cat. No. 


60-60 MHz 


060-1 


60-80 MHz 


060-2 


80-95 MHz 


080-1 


80-95 MHz 


080-2 


95-125 MHz 


095-1 


95-150 MHz 


095-2 


110-160 MHz 


110-1 


150-250 MHz 


150-2 


150^250 MHz 


150-1 


200-300 MHz 


200-2 


200-300 MHz 


2001 


250-450 MHz 


250-2 


275-450 MHz 


2?5-1 


400-850 MHz 


400-2 


425-850 MHz 


425-1 


800-950 MHz 


800-2 


800-950 MHz 


800-1 








NATION AL RADIO COMPANY, INC. 

NRCi 







NCX-1000 

The only IDQO watt, "single package" 
transceiver. Heavy duty design . . . results 
of 50 yeuisaf design leadership in amateur 
equipnnent. State of the art speech pro- 
cessing, linear amplifier, power supply, ail 
in one package. Nothing extra to buy. 
Covers all amateur bands in the HF 
spectrum . . . AM, SS' CW dj-i Cftn 



NCL-2000 

Linear Amplifier. A full 10 dB gain. 2D 
watts in 2000 vuatts out. Can be driven 
with one watt. Continuous duly design 
utilizes [wo 8122 csrsmic tetrode cuipu! 
tubes, designed for both A?.1 and SSB 
operation. The industry standard for 12 
years. Thousands In use ali over the world. 



$1,200 




■ 




HRO-500 



Ti ~"r 



The ultimate short wave receiver. This synthesized (phase lod< loop) receiver incurpo- 
rstes all facilities for AlW, Single Side Band (SSB), and CW receiption in all frequencies 
from the bottom of the very low freqtiency band (VLF) to the lop of the high fre- 
quency band (HFl. [^atJonaCs "dead accurate" dial means no searching for Itans- 
missions. Dial up the frequency and it's there: aeronautical, marine, CB, amateur, 
military, etc. Continuous coverage. ^^ nnn 



USED GEAR • TRADE UP • FREE UPS SHIPPING ON PREPAID ORDERS 



$2,000,000 HAM INVENTORY 



i 




ICOM 



VHF/UHF AMATEUR 
& MARINE EQUIPMENT 




VHF/UHF AMATEUR 
& MARINE EQUIPMENT 

IC-245. 146 r/Hz FM !0W XCVR. LSI 
synthesizer with 4 digil LED readout. 
Xmii & Rev frequencies independently 
programmahlB. 60 dB spurious attenua- 
tion. 



$499.00 




IC-211 



iC-211. 4 MEG, MULTI-MODE 2IVI 
XCVR. 144-145 MHz on SSB & CW, 
plus 146-147 MHz on FM. Work AMAT 
OSCAR six or seven. LSI synthesizer 
with 7 digit LED. MOS FET RF Amp, 
5 helicai cavities, FET mixer & 3 i.F. 
filters. 



$749.00 



IC-215. 2 METER FP/ PORTABLE. 
Three narrow filters for superb perform- 
ance. 3W or 400 mW. 15 CH. capacity. 
MOS FET RF Amp & 5 tuned ckts. 
S meter front panel. *fi??Q fin 




$249.00 




IC-5D2. 6 METER SSB & CW PORTA- 
BLE XCVR. Includes antenna & battery 
pack. 3VT/ PEP & stable VFO for fun & 
FB QSQ's. Covers first 800 KHz of 6M 
hand, wiiere most activity is. 



$299.00 




IC-Z2S. 145 MHz FM lOW XCVR. CMOS synthesizer can be salio any 15 KHz ch. between 
146 & 148 MHz by diode matrix board. Spurious attenuation far better than FCC spec. lOW 
or IW, IDC moduiation centrcl. 



o 

I 




IC-21A. 146 MHz FM lOW XCVR. MOS 
FET RF Amp & 5 helicai resonator 
filter, plus 3 I.F. filters. IDC modtilatiGn 
control. Variable output pwr: 500 PjIW 
to lOvV Front panel discriminator meter. 
SWR bridge. 117 VAC and 13.6 VDC 
pwr supplies. $399.00 

DV-21. DIGITAL VFO. Use with IC- 
21 A to complete 2M band. 



$299.00 



IC-202. 2 METER SSB 
PORTABLE XCVR. Puts 
sideband in your hand! 
Internal C batteries or ex- 
ternal 12 VDC. 3W PEP. 
True I.F. noise blanker. 
144,0, 144.2 on two other 
200KHzban[is,selectabl8. 
Haintronics stocks 145.2 
end 145,8- 146,0 MHz for 
calling frequency & sateU 



$259.00 





%/i 



IC-30A. 450 MHz FM LOW XCVR. IW 
or lOVl'. Low noise MOS-FET RF Amp 
& 5 section helical filter. 22 CH. 
capacity. S-meter & relative power out- 
put meter. IDC modulation control. 



$399.00 



MASTERCHARGE & BANKAMERICARD ACCEPTED 



!f-^:U::»K' ![«<-= 



DIVISION OF TREVOSE ELECTRONICS 

4033 Brownsville Rd • Trevose, Pa. 19047 

(215)357-1400/(21 5) 757-5300 



1 



mi'mi\iir\mm 



«A 



5 

I 



TEMPO 




TEMPO OWE 

AC/ONE 

VF/ONE 

TEMPO VHF/ONE 

TEMPO SSB/ONE 

TEMPO 2020 

FMH 

RBF-I 
DM-20 

MS-2 



HF Transceiver. 80-lOM. USB, 

CW & AM 399.00 

Power Supply for TEMPO 

ONE 99.00 

External VFO for TEMPO 

ONE 109.00 

Transceiver. 2[W. M4 yo 148 

IVIHz. PLL 399.00 

SSB Adapter for TEMPO 

VHF/ONE 199.00 

Transceiver. 80-10M. USB, 

LSB, CW and AM. PLL. 

Digital 759.00 

2W, VHF/FM, 6 Ch. Hand 

Held. 144-148 MHz 199.00 

Wattrrieter & SWR Bridge 42.95 

Desk Mike. 600 or [50K ofim. 

PTT & Lock Switches 39.00 

4 Ch. Pocket Scanning Rcvr. 99.00 



ATLAS 



21 ox Transceiver. 10-80M. 2G0W 679.00 

215X Transceiver. 15-1 60M. 200VV 679.00 

OMK Dehrxe iVItg. Kit for 21QX & 

21SX 48,00 

220CS AC Console for 21 OX & 21 5X 149.00 

350-XL Transceiver. SSB. Solid State. 

10-16QM. 350W. 995.00 

DD6-XL Digital Dial Readout for 350- 

XL 195.00 

306 Plug-In Auxiliary VFO. For 

350-XL 155.00 

311 Plug-In Auxiliary Crystal Os- 

cillator for 350-XL 135.00 

350-PS AC Pivr Supply w/Spkr Si 

Phone Jack for 350XL 195.00 

DMK-XL Mobile IVIounting Bracket for 

350-XL. Easy Plug-In 65.00 



SWAN 





700 ex 

VX-2 
SS-16B 

MARK II 
1200X 



FC76 
WM6200 

FS-2 

SWR-3 

SWR-1A 

W2000 

WM-3000 

FS-1 
WM1500 

MARK It 
1200 X 



Transceiver. 700W PEP. SSB. 
S0-10M. USB, LSBorCW 
Piug-ln VOX for 700 CX 
Super Selective IF Filter for 
700 CX 

Linear Amplifierc Full Legal 
Power. W/100W input. SO-10 
M. 

Portable Linear Amplifier. 
1200W PEP. SSB. 700W, Cti. 
300W, AM. 80-1 OM. 
Hybrid Telephone Patch. Con- 
nect Rcvr/Xmitler to Phone 
iinas 



649.95 
44.95 

99.95 



849.95 



349.95 



64,95 




Frequency Counter. 5 Digit 

LED 169.95 

In-Line Presicion Wattniater 

for 2M. 2 Scales to 200W. 

Reads SWR. ._ 59.95 

SWR & Field Strength Meter 15.95 

Pocket SWR Meter 12.95 

Relative Power Meter & SWR 

Bridge 25.95 

in-Line Wattmeter. 3 Scales 

to 2000W. 3.5 to 30 MHz 59.95 

Peak/RMS Wattmeter. Tells 

The Truth About SSB 79.95 

Pocket Field Strength Meter 10.95 

In-Line Wattmeter. 4 Scales 

to 1500W, 2 to50 MHz 74.95 



Linear Amplifier. Full Legal 

Power. W/100W input. 80-10 

M. 849.95 

Portable Linear Amplifier. 

1200W PEP. SSB. 700W, CW. 

30OVI, AM. 80-1 OM. 349.95 



USED GEAR • TRADE UP • FREE UPS SHIPPING ON PREPAID ORDERS 




NYE VIKING 




No. 114-310-003 S8.25 No. 114-310-004GP $50.00 No. 114-404-002 $18.50 



No. SSK-1 $23.95 






No. 250-46-1 $36.50 No. 250-46-3 $44.50 



No. 250-20-1 $19.95 No. 250-0025-003 $212 



NPC 



2.5 AMP 



4 AMP 



6 AMP 







^. 



^^v*^* 



Mjt^'OL- 





12CB4 29.95 



103R 39.95 



104R 49.95 



12 AMP 

108 RM 
99.95 



!t 


r'^j^ ^ 


• 




'i- 






25 AMP 
109R 149.95 



VIBROPLEX 




"PRESENTATION" 
72.50 



'ORIGINAL" 
49.95 



'LIGHTNING BUG' 
49.95 



"CHAMPION" 
46.50 




VIBRO-KEYER 
46.50 



MASTERCHARGE & BANKAMERICARD ACCEPTED 



^ ^ If 



DIVISION OF TREVOSE ELECTRONICS 
4033 BrownsviMe Rd • Trevose, Pa. 19047 

^215) 357-1400/(215) 757-5300 



DenlfOTL. 



3 Kilovratt Tuner Matches 
Everything From 160 to 10 



160- 10 MAT 

Built-in 
Wattmeter 

Front Panel Antenna 
Selector for 
Coax, Balanced 
Line and Random 
Wire. 




only $299.50 



o 

S 




Super 
Tuner 



160-10 Meters 
Balanced Line, 
Coax, Random 
or Long Wire 
Maximum Power Transfer, Xmitterto Antenna. 

1 KW Model $1 29.50 3 KW Model $229.50 



1000 to 1200 WATTS OUTPUT 
TO YOUR ANTENNA 

Den^OTL. SUPERAMP 




$499.50 



\t the ampfittEf you're thinking r>f buying doesn't c^e liver at lean lOOO to 1200 w-atls output, 

10 the ar>!erina, vou'r^ buying the wrong amplifier. 

Our New S^|pe^ Amp is sViitMping the country hgcause hams have realized that th# OenTron 

Amplifier will deliver to the antenna, (ouTput power), what other manufacturers rate as input 

powe-j", 

The Super Amp runs a full 2000 rti5tti P.E.P, input on SSB, and lOOO watts DC On CW." RTTY 

or SSTV 1B0-10 meters, the ma:* i mum fcgaf powei. 

TTit Supei P^mp is compact, low profile, has 3 solid one-piece calJintl aisuring maximum TVI 

AeildirtQ. 

The heart o( our amplrfier, ihe powe' supply, it a continuous duty, self -contained supply buiH 

for contest perform snce. 

We mnaumed the 4 - 811 A's, industiiai workhorse tubes. In a cooling chan^ber fearunng the 
on-den?and vari^bJe cooling tystem. 

The hams at DsnTron pride themwives on qualiry work, ^nd we 'ight to keep prices down. TTiat's 
why the dynamic DenTron Linear Amoiifier beats rhem all at S499.G0, 



NOW AVAILABLE WITH 57? B' FOR 



$574.50 



1 

I 



DenlfOTL. ANTENNAS 

The Sky Openers 



SKVTV! ASTER 

A fully developed and Kiud 27 Tool 
v^iticill aniannc wvpji entire 10, 1&, Zg, 
3iid40mi]larb3nds using onlv ana cFev^rly 
^jpiptidd WDVCtr^p. A full 1/4 wove eiitnnra 
on 20 malQri. Canitruct'Sd of heiivy leriirt- 
leji al^irtinum with a fatrlorv tonod nnd 
sealed HQTiap. SKVMASTEfl it. ^sihei 
proof drldwilhiljjnds wind^-ijp 1d0O rrph. 
H^rKilu 2 KVi r>auver 1ek-e1 and ii io, 
^cUrid, r6of o( towet mounung. Rad'Mli 
irtduded \n our fo^ p'ic^ of 

$84.50 

Abo &0 m reiorutor for loc maLnting on 
SKVMASTtR, 




DefUfOTL. ANTENNA TUNER 

Th£ 80-10 ShymatcHer 

Kerb's aiT anlenna lunSr fot SO ihraegh_JO niDlers. handler £00 w P.E.P_ ancf m&1r;hes yoyr 
52 ohm transceiver to a r.indom wir^ antenna. 



S29.5O 



^^ 



SKYCLAVy 

A tUnablo Inonoband high performancR 
venicar antenna, d^igred tor 40. QO, 1 GO 
melei Op«r»iEan. SKYCLAW ^\tei you 
tiiB toJEowing lipeciruirv coV'Sia^: 
BAhTD SANDWIDTH 



TRIM-TENWA 

The in\kviji^ VOUJ' ll[7i<^>itipit vi\\ \o'J^- The 
new DsrTrori Tun Trnnj wih 20 it>&iw 
beam ii dtifgii'd for the diswiniiijaJinj 
inatc-u' MT^o viznxi itKWtbe, rte-rforrrtance 
ii an en^' iron menial Iv appVij-ling beem. 1 1*3 
■4311 V \ti3A6A\ Up fi^ni it^eii^'i ^ ]3fcai 
6 inch director wiih ptrdt or Hy-Cl c«li. 
Ard. T teet beliitid ■! « 16 fooT itineJi 
eFsfnan fed diiectiy wiiTi 52 ahrj coaK. 
TTi- TriTTiTimra mai^nt^ «anly and whsi 
a diflerenca in on-ihe-nii p^rfoimancs be- 
twai]ri ihg Triin Tenna and that dLpvl'i, 
long wire or inuuiwd Vcf you've bean 
using. 4 & S Parkvurd Gjiln Over Difxile. 







- Comi iiLjous tuning 3.2 - 30 mc 
* "L" network 

■ Ceraniit 1? position rotary switch 
' SO— 239 rpceptlonai to trartjmirter 

■ Random wire Turner 

■ 3MQ vol", capacitor spac'rn^ 

■ Tapped inductor 

' Ce^gmic antenna feed thru 

. 7" W, 5" H. 6" 0.. ft-eight: S lbs. 



$59.50 



$IZ9.50 



160 



50 



SO 2no 

^0 ■sf'tirf bimJ 

Turviftg ii «aiv ind r^rc^ble. Rugged con- 
TtruEti-On iljuvn ihsl thij ietf-iOpportin-g 
uTiit ii iiii^aih'0/p'ocf ^nd i\iT*i*t\ n<4#lv 




100 I 



windi.. Handlei full legal 

$79.50 



EX-1 

The DinTroR EX-1 Vertical Antenna ii 
dnigrrfd for l^c pedoiniariM mirrfed 
amema e'xpM'i rammer. The EX-l 11 a f jll 
40 meler, '^ watt, 3?, leH-Hjpportirrg 
Yertjcj!- The EX-t is ^^ idtil vrriical 
tor ptu:\inff. 



$59.50 



ALL eAHD DOUBLET 
TUrt All Bard Doublui or invenad TypA 
Antenna aneii 160 thru 10 nteiirS. Ha* 
tool E^ncpb of 1J0 f^ei {M gi;. slrsncfad 
copper) a-lthough it may be risd'5 ihortSI 
if necviiSdry^ Thif tuied Doublet, is center 
fvd t>irouQh ICO ItEl of 450 ohm PVC 
Covered b9[«no«d Trjni.m1>iion line, Tha 
qi^i^jTibly 'i fomplet^-. AdO lope ia the 
'endi '^n'rj puil up into petition. Tune 
witti tfi* DenTron Sup«r Tunsr and 
you're on 10 ihrouch 160 meisis with 
nnc anunna: Now jjti tor rhs DenTron 
All Band Doublet. _ 

$24.50 



Denlron. W-2 PAD 
INLINE WATTMASTER 

Read forward 
and reflected 
watts at the 
same time 



Tired of constant s^vilching and gjesiwork^ 

EvCy WIIOU5 tiam knows he must reed both foru/ard and reverse vv^tteg^ ^imukarwou^ly 

for Ih3t perfect maith. So upgrade vjiih tiie DenTron \V-2 Dual in line Wamfleier. 




$99.50 



USED GEAR • TRADE UP • FREE UPS SHIPPING ON PREPAID ORDERS 



$2,000,000 HAM INVENTORY 



■iinr.ivii^ij.rnni 



IKIF 



TEIM-TEC 



INC. 



TRITON IV 
EQUIPMENT 





MODEL 240 $97.00 

ONE - SIXTY CONVERTER 



MODEL Se49 $169.00 

REMOTE VFO 



TRANSCEIVERS 

MODEL 540-200W, SSB/CW 
3.5 - 30 MHz $699.00 

MODEL 544- DIGITAL, 200W 
SSB/CW, 3.5-30 MHz 

S869.00 





MODEL 244 $197.00 

DIGITAL READ OUT/COUNTER 



MODEL 262-G $139.00 

DELUXE POWER SUPPLY 



ARGONAUT 




VF 



"■■" -^^-^ .. ' vJt y 01 



<>o 



MODEL 509 $359.00 

SW, SSB/CW, 3.5-30 MHz 





AMMETER 
207 $14.00 



XTAL CALIBRATOR 
206 $29.00 



LINEAR AMPLIFIER 

MODEL 405 $159.00 
100W, 3.5 - 30 MHz 





KEYERS 




ELECTRONIC KR-50 
$110.00 



ELEaRONIC 

KR20-A $69.50 






ELEaRONIC KR-5A 
$39.50 



KR-2A 



$17.00 



KR1-A 



$35.00 



MASTERCHARGE & BANKAMERICARD ACCEPTED 



mM 



DIVISION OF TREVOSE ELECTRONICS 

4033 Brownsville Rd • Trevose, Pa. 19047 

(215) 357-1400/(215) 757-5300 



the latest gear 
for the VHF enthusiast 



ssHnBER-ejaHnsan 




Gamber-Johnson 
Deluxe slide mount 
$1 7.88 

• Solid snap in design 

• Attaches to radio 
mtg bkt (or directly 
to radio) 

• Four molex pins for 
power and external 
speaker 

• BNC RF slide 
connector 

• pigtail UHF 
(SO-233) 
connections to 
radio and antenna 

• designed for 
commercial use 
thru 1000 MH3 



Gamber-Johnson 
Console floor mount 
$31.50 

• utilizes deluxe slide 
mount 

• built in speaker 

• mount attaches 
securely to floor 

extra slide mount 

base $8.40 

stationary half of deluxe 
slidemount allows use of 
radio in second car or 
location 






% 



Frequency Register Search Indicator Scan or Search 
_v \ ^ 




Program Panel Channel Panel 16 Scanning L.E.D.'s 



Regency Digitally Prog 
with Keyboard Entry 

Model ACT^T-16K 

Frequency Range: 
Lo VHF .. 30- 50MHz 
Hi VHF . 146-174 MHz 
UHF . 440-512 MH2 

Sensitivity: 

(20 DB quieting) 

Lo VHF 0.5 /i. V 

Hi VHF 0.6 K V 

UHF 0.7 jx V 



rammable Scanner 
special $299 

Selectivity 

± 7 KHz (min.) @ 6 DB 
- 15 KHz (max.) @ 60 DB 

Squelch: (threshold) 

Lo VHF 0,4 pt, V 

Hi VHF 0.5 At V 

UHF 0.6 /i V 

Search Scan Range: (max) 

Lo VHF 4000 channels 

Hi VHF 5600 channels 

UHF 5760 channels 



uiciT<om 



Westcom 
VHF Amplifiers 




Mode! Band Efiiission 

2M 3x30 144MHz FM 1 

2ff. 3x30L 144MHz CW-FV1-SSB;AM 1 

2M 10x40 1<WMHz FM 2 

2M 15x80 IMMHz FM 5 

2M ISxSOL IMMHz CW-FM-SSS/AM 5 



Pout 
30 
30 
1C 
80 
SO 



Price 
72.95 
32.85 
77.95 
129.95 
'39.96 




Ruggedized DC 
Power Supplies 

Ideal for VHF Transceivers 
and Amplifiers 

• 105-125 VAC, 50/60 Hz 

• Fold back current limiting 

• 13.8 VDC + .05V 

• UL listed & computer grade componehtS 

• One year warranty 

• 5 mV peak-peak max ripple 

Astron RS-20A S89.95 

16 ADC Continuous 
20 ADC Intermitlant 
Recommended for up lo 
120 W amp's 



Astron RS-6A $49.95 

4.5 ADC Continuous 
6.0 ADC Intermittant 
Recommended for up to 
30 W amp's & xcvrs 



Astron RS-10AS74.95 

8 ADC Continuous 
10 ADC Intermittant 
Recommended for up to 
70 W amp's 



Astron RS-35A $'l59.95 

25 ADC Continuous 
3B mc Intermittant 
Recommended for up to 
180 W amp's 



Electronics.nc 

Larsen mobile antennas 

Vs wave, 3de gain, 200 W rating 

LM-150-K 2M roof mount $30.20 

LM-150 w/magnetic mount $38.45 

LM-150 w/trunk lid mount S37.90 

for i\/lotorola NMO type mount add $5.25 
220 MHz and 450 MHz availableat same price 



Master Charge & B of A 
We ship prepaid in USA 
Calif, residents add 6% tax 
Check with order or COD 



10 day money back guarantee 
full satisfaction guaranteed 
Factory warranty on all items 

W17 




134 



This article describes a 
simple wind speed indi- 
cator which can be built very 
inexpensively and is complete 
within itself. It can be con- 
structed as just a fun project 
or cari have a serious applica- 
tion in functioning as an 
alarm indicator to indicate 
that a certain wind speed is 
being exceeded and a beam 
should be lowered. For those 
who desire to build a more 
precise anemometer, refer to 
the article "Inherit the 
Wind," 73 for March, 1976. 
[t describes a very good home 
brew wind speed indicator. 
Its advantages are accuracy 
and the detection of low 
wind speeds. It requires a bit 
of circuitry, a power supply 
and a frequency counter as an 
indicator. The wind speed 
article described in this article 
is far from that elaborate, 
however; it requires no power 
supply, is a self-contained 
unit, and can serve the basic 
purpose of "saving your 
beam." 

The heart of any wind 
speed indicator is a device 
that will generate and/or 
transmit a voltage propor- 
tional to the speed at which 
the wind vanes are rotating. 
Quite by accident, it was dis- 
covered that the dc motors 
found in cassette tape players 
make excellent little dc 
voltage generators when their 
shaft is externally rotated. 
These motors are inexpensive 
but relatively well-made as a 
mass-produced item. Their 
bearings are good enough that 
they should last for several 
years of service and of low 
enough friction that a 
moderate size wind vane will 
start the shaft turning in any- 
thing more than a gentle 



73 Magazine Staff 



PLASTIC JAR COVER, 
2 f/2ir! DIA 




STRAfNERS, 
EA. ABOUT 
ein OVERALL 
LEWGTH 



Straining the Wind 

- - simple wind speed indicator 



breeze. They can be pur- 
chased from various surplus 
outlets for a few dollars, or 
almost any serviceman will 
have a few available from 
discarded cassette tape 
players. Don't confuse this 
type of motor, however, with 
the "cheapie" dc motors used 
in toys. TTie latter type of 
motor will work also as a dc 
voltage generator, but will 
last only a short while in 
continuous rotational service. 

The motor-turned-genera- 
tor can be secured to a mast 
with a large hose clamp, or a 
much neater mast mounting 
arrangement can be made 
using a bell-type reducing 
joint. The latter can be found 
in plumbing supply houses. 
They are meant to join pipes 
with fairly great thread 
diameter changes. Usually 
one can be found which will 
mate with a desired mast 
diameter, and the large end of 
the bell joint then forms a 
cup into which the dc genera- 
tor can be snugly fitted and 
glued into place. 

The construction of the 
wind vanes can be as simple 
or as elaborate as one desires. 
The overall dimensions shown 
in Fig. 1 yielded good results 
with winds ranging from a bit 
more than a light breeze to 
gale force winds. The 
principal requirement is that 
the vanes turn in one direc- 
tion only or else the genera- 
tor will not always produce a 



voltage of the same polarity. 
To ensure this, some sort of 
cup or cone assembly is 
needed at the end of each 
vane. The assembly shown in 
Fig. 1 is about as simple as 
one can get. The center piece 
of the vane assembly is a 
plastic cover from a large 
glass jar. It serves two pur- 
poses. One is to act as ' a 
central mounting piece for 
the vanes, and it also serves, 
because of its shape, as a 
weather cover for the upper 
part of the generator. The 
generator used had a pulley.,^ 
permanently attached to the 
shaft, and apparently most all 
cassette motors come this 
way. The end of the pulley 
was filed flat and then the jar'"' 
cover fastened to it with 
epoxy cement. The individual 
vanes are simply plastic sauce 
strainers found in a house- 
hold goods store. The strainer 
holes are sealed up by 
painting them, and the handle 
end is secured to the jar cover 
by some screws. The whole 
assembly does look a bit 
funny, to say the least, but it 
works. It can be made a bit 
more professional-looking by 
a good overall aluminum 
spray painting. Also, once it 
is up in the air, the simple 
components of its construc- 
tion are no longer as obvious. 
The generator voltage is 
transferred by regular line 
cord to a remote indicator. 



The remote indicator can be a 
simple meter or something 
more elaborate, like a digital 
readout. The generator will 
turn fast enough to easily 
activate a microampere 
meter even over long transfer 
line lengths. In very high 
winds, enough voltage will be 
generated to activate an LED. 
Fig. 2 shows a remote indi- 
cator circuit using a 1 50 uA 
meter. An adjustment poten- 
tiometer allows the meter to 
be set for full scale with a 
strong wind blowing. The 
optoisolator circuit (an LED 
and a switching transistor in 
an IC package) can be used to 
switch on a buzzer or bell 
when a particularly high wind 
gust is sensed. The main value 
of this feature is that one can 
be alerted, usually during the 
night, of the presence of a 
high wind condition. The 
meter=- can be approximately 
calibrated in wind speed 
values by comparing its 
reading to locally broadcast 
weather reports under various 
wind conditions, ■ 



TO GENERATOR 



■;K SENSITJVITY 




TO DESIRED 

ALARM 

CIRCUITRY 



-OPTO-!SDLATQR, 
SPRAGUE ED702 
OR RADIO SRACK 
OR HEP EQUIV. 



Fig. 1. Advanced design wind vane assembly. 



Fig. 2. Remote indicator. Alarm circuitry migJit be a 6 volt 
battery in series with a l^allory Sonalert, for example. 



135 



Ralph A. Giffone N2RG 
963 E. 105 Sireet 
Brooklyn NY 11236 



Find That 
Meter Resistance 



-- with this simple bridge 



There comes a time in 
every ham's life when 
he must seel< that unknown 
meter resistance. Here's a 
simple solution to that age- 
old problem. The schematic is 
shown in Fig. 1. It's equiva- 
lent circuit Js shown in Figs. 
2(a) and 2(b). 

In Fig. 2(b), R2 is equal to 
R2, and Rgp is the equivalent 
parallel resistance of branch 1 
and branch 2. Neglecting 
Rgp, the current through R2 




would be 1.5 (E)./1500 (R) = 
.001 A or 1 mA, the full-scale 
reading of most meters. Thus, 
when we reinsert RbPj we 
know that the current is less 
than 1 mA. This keeps the 
current through each branch 
(Fig. 1) less than 1 mA, pro- 
tecting both meters. 

in Figs. I and 2(a), when 
the resistance of branch one 
is equal to the resistance of 
branch two, the currents 
through both are equal. Thus, 
you know that when the 
reading on the meter under 




test and the current reading 
on your meter are equal, the 
resistances of the twg 
branches are equal. 

The resistance of branch 
one is equal to the resistance 
of Ml (which must be 
known) plus Rl, a poten-" 
tiometer with a calibrated 
dial. If we select Rx so that it 
is equal to R^i, then, when 
Rl is equal to RjVI-testj ^^^ 
resistances of the branches 
are equal, if the resistances of 
each branch are equal, the 
currents through them are 
equal. 

To find the meter resis- 
tance, one must plug in the 
meter under test and rotate 



Rl until the currents through 
both meters are equal. I'hen 
we know that Rl = RM-test 
and its resistance can be read 
directly off the calibrated 
dial. 

The smaller the value of 
potentiometer Rl , the more 
accurate is the measusement 
of R|Vl-test- This is because 
the dial can be calibrated in 
smaller units. 

As an option, a more ac- 
CLirate circuit is shown in Fig. 
3. A rotary switch can select 
different values of resistance 
to be added to Rl . Thus, Rl 
can be made as small as you 
wish. RjVl-test is now equal to 
Rl plus the switched-in resis- 
tance. 

Let's say you wanted to 
measure a meter's resistance 
using only Rl (Fig. l). If 
your dial was calibrated with 
100 notches, the result would 
be 5 Ohms per notch. If we 
use the circtiit in Fig. 3, the 
potentiometer is only 200 
Ohms, leaving 2 Ohms per 
notch on the same calibrated 
dial. Thus, we see how there 
is more accuracy in a circuit 
such as the one shown in Fig. 
3. 

I would suggest that you 
choose a meter with a low 
" resistance. Also, if you prefer, 
you can use an ohmmeter to 
read the resistance of Rl, 
thus saving yourself the 
■ trouble of finding a calibrated 
dial. 

As you can see, the circuit 
is a flexible one and can be 
customized by the builder. 
All tlj_at is needed is a pen, 
paper and E = I R. ■ 




Fig. J. 



Fig. 2(a). 



Fig. 2(b). 



Fig. 3. 



136 



JRN 




''Right 
on" 

with 
Jan 
Crystals 

for 

• General Communication & Industry 

• Citizen's Band 
(Standard & Synthesized) 

■ Two-Meter - Monitor - Scanners 

• Marine VHP * Amateur Bands 

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• High Perlormsnce 

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all phones (813) 936-2397 

I J2 




*1HE PROFESSIONALS" 

Hilfli ELECTRONICS 



500 MHz 
and 1 GHz 
Counters 



FREQUENCY COUNTER 



S0Q.31BHB 



nut 






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The CTR-2 Series Counters are designed and built to the highest standards to fulfil! the 
needs of commercial comnriunications, engineering iabs and serious experimentors. With an 
accuracv of ± .00005% (o\/en option) the CTR-2 can handle the most critical measurements 
and is about haJf the cost of other commercial counters. 

If vou need a reliahie counter at an affordable price, the CTR-2 is the answer. 



8 Digit .3" LED Display 
High Stability TCXO Time Base 
Built-in VHF-UHF Prescaler 
Automatic Dp Placement 
TCXO Std. i 2 ppm 



• input Diode Protected 

• 12V-DC Operation (Optional) 

• Oven Controlled Crystal (Optional) 
± .5 ppm 

• Selectible Gate Times 



RANGE 

500 MHz Kit <: 

500 MHz Assem 
1 GHz Kit CT( 
1 GHz Assemble 


CTR-2-500 CTR-2-1000 

10 Hz to 512 MHz 10 Hz to > 1000 MHz 


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bled CTR 2-500A 349.95 

=1-2-1 OOOK 399.95 

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'^NO TRAPS - NO COILS - NO STUBS - NO CAPACITORS 

MOR-G A1 W HD DIPOl R-'? , . , #006 haif the length of con ven tioral 
half-vvave dipbies. • tVluM i-ij.;tnd, Multi-frequency. • (VlaximiBrn effi' 
cienLV — no traps, loading coils, or stubs. • Pulty ass^inblucf cirtd 
pre-tuned — na Pleasuring, no cutting. •AH weather rated — 1 KW AM, 
2.5 KW CW or PEP SSB. •Proven performance - more than 15,000 
have been dn! [wst ciJ , • Permit use «< thn full capabilities of tocbiv'? 
5-band xcvrs. * One feedline for oiiqraricin on all bands, • Loinmst 
cost/benerf't antenna on the market lodflv. • Fast OSY — no t(Midl|rte 
switching. • Highecr performance for the Novice as well aa tfie 
Extia-CljiSft Op. 



EXCLUSIVE 66 FOOT, 7S THRU 10 METER DIPOLES 

NOTES 

V AM m-od^s above are furnished with criinp/soider tugs. 

U AH Tt^odeJs can be furnished with a SO -239 female coaxiaE connector 

at additiorsal cost. The SO 239 nnates vuitti the Aandard PL 259 male 

coaxial cable connector. To order this factory installed option, add the 

letter 'A' after the model number. Example: 40-30 HD/A. 

■ 75 meter models are factory tuned to resonate at 3950 kHz. (SP) 

models are factory toned to resonate atSSQO kHz. 80 meter models are 

factory tuned to resonate at 3650 kHz. See VSWR curves for other 

resonance data. 



' l^t'va - /frguar/JoJF At/eaav in Use 



TtIS 40% Copper WslfJ wire annealed so ithand/BS like soft Copper 
wire ~ Rated fm hstlsr than full Isgaf power A!i4/CW or 
SSli-Coa}<ial or Baiani:^ 50 to 75 aftrr) fpsfl line — VSWfi under i,5 
to 1 at fiio%t I'iiiijiiiS ' Sisinfess Steel ^rHWarii - Drop frouf 
Insulators - Terrific Parforniancw — No cciiJi ar trspi to hreak dov/n 
or ctiange under M/satfifiF €ondltiitn$ — Cottiffi-stelv Assemliled rasdy 
to put up - GulrEirrtectf / year - OlVE' D£SIGM DOBS IT ALL- 
75- WHO - OPJL Y $12MA BAND! 



WUDlt 

49-70 HD 
80-40 HD 
^Saehl^ 

7545 HTJ ISP! 

7SS1I HO ISP) 

75-10*lDi5Pl 
SfHOHO 



I^AWDS 
IM11*>1 

8a'40i IS 

TS.40 
7S'40 

7S,l»f}I}.lS,l|0 
9(lr«'2a'15rlo 



PRICE 

S49 59 

56-430 

74 60 
76 60 



WEIGHT 

4>.'i.l5 
it'? ?7 
4a'1.l!5 
44,1.23 
44f'l.Jil 
4a.'i.a* 

S0.fi.40 




2200T South 4tfi Street 
Leavenworth, Kansas 6604S 

1913) 682 3142 



BaJi^AmrTDi^ ^. liUEkT i:hJTg( jvailaMe 



ffiggBBlM]) 



Manufactured & Guaranteed by 
MOR-GAIN 



LEJJ&TH 
iFi.-farsI 
39/109 
(14,12 !.0 
ESfTO I 
B6.-?(i1 

Ea.'i(i 1 

MrSft. 1 
ES.-'TH 1 
i?.'7t.O 




137 



CaUlbUFree 

1*800*633*34]0 

for HF transceiveirs 




TEN-TEC Century 21 
novice/CW transceiver 

Features: • Full break-in • 70 watts 
input • Solid-state • Built-in speaker 

• Receives CW or SSB • Instant band 
Change • Offset receiver tuning 

• Overload protection • Sidetone with 
adjustable level • Regula'ed power 
supply* 80 thru 20 meters vi^ith crystals 
supplied. 

289.00 list price- Call for quote. 




TEN-TEC Triton IV 
digital HF transceiver 

Triton IV features: • 3.5 to 30 MHz 
coverage" Totally solid-state* Instant 
band change • 8-pole crystal IF filter 

• Large LED digital readout • 200W 
input all bands • WWV at 10 & 15 MHz 

• Full CW break-in* S-meterandSWR 
bridge* 100% duty cycle, full power for 
RTTY & SSTV. 

869.00 list price. Call for quote. 




DRAKE 

TR-4CW transceiver 

TR-4CW covers 80 thru 10 meters 

• Modes: SSB, AM, CW • 300 watts 
PEP input: SSB, 260 watts: AM & CW 

• Transceive or separate PTO • Wide 
range' receiving AGC • Solid-state 
VFO • CW semi-break-in • VOX or 
PTT • Shifted-carrier CW * Constant 
calibration mode to mode.., 

699.00 list price. Call for quote. 




YAESU 

FT-101E transceiver 

FT-101E is completely solid-state 

• Coverage: 160 thru 10 meters* Built- 
in AC/DC power supplies • Built-in RF 
speech processor * 260 watts PEP: 
SSB, ISO watts: CW, 80 watts: AM 

• Solid-stale VFO* VOX* Auto break- 
in CW sidetone • WWV/JJY reception 

• Heater switch. 

729.00 list price. Call for quote. 




The NEW KENWOOD 
TS-820S transceiver 

TS-820S now has factory installed 
digital readout • 160 thru 10 meter 
coverage • 200 watts PEP* Integral IF 
shift * Noise blanker -VOX & PLL 
circuitry • DRS dial • IF out, RTTY, 
XVTR capabilities • Phone patch IM 
and OUT terminals * RF speech 
processor. 

1048.00 list price. Call for quote. 




HYGAIN 3750 
HF transceiver 

The 3750 is the ultimate transceiver. 
•Covers 160 thru 10 meters • Ad- 
vanced PLL* Narrow tiand SSB crystal 
filter .eliminates receiver image & 
spurious response problems * 200 
watts input • Gated, adjustable noise 
blanker • Transmitter has audio com- 
pression circuit & auto level control 
• And so much more! 



1895.00 



list price. Call for quote. 



Remember, you can call TOLL-FREE: 1-800-633-3410 in U.S.A. or call 1-800-292-8668 in 
Alabama for our low price quote. Store hours: 9:00 AM til 5:30 PM, Monday thru Friday. 

Long s Elec^tronics . 





MAIL ORDERS: P.O. BOX 1 1347 BIRMINGHAM. AL 35202 • STREET ADDRESS: 3521 lOTH AVENUE h40RTH BIRMINGHAM, ALABAMA 35234 
138 



CaUlbUFree 

1*800*633*3^0 

for 2in transceivers 




KENWOOD TR-7500 
2ni transceiver 

The TR-7500: • PLL synthe- 
sized • 100 channels (88 pre- 
programed, 12 extras are diode 
programmable) • Single-knob chan- 
nel selection • 2-digit LED frequency 
display • Powered tone pad connec- 
tion • 10 watts HI output, 1 watt LOW 
output. 

299.00 list price. Call for quote. 



i 



WILSON 1405 
SM 2m hand- 
held radio 

6 channel operation 

• O.Smicro volt sen- 
sitivity • 12 KHz 
ceramic filter • In- 
dividual trimmers on 
all TX/RX crystals 

• 10.7 & 445 KHz IF 

• Sw/itchable 5W or 
1W output • Touch- 
tone pad included • 
Recharger base 
available. 

339.90 list price. 
Call for quote. 





ICOIVI IC-245 
2m transceiver 

lC-245 has: • LSI synthesizer 
PLL • 4-digit LED readout* Transmit 
& receiver frequencies are in- 
dependently programmable on any 
separation • TX output: 10 W 
PEP • Receiver front-end is a balance 
of low-noise, high-gain MOS FET & a 5 
section filter. 

499.00 list price. Call for quote. 




YAESU FT-221R 
2m transceiver 

144 to 148 MHz coverage in 8 bani< 
segments • Built-in AC/DC power 
supply • Modes: SSB, CW, FM, 
AM •■ VOX • CW break-in • PLL 
circuitry • Noise blanker • Externa) 
toucfi pad connector • 11 crystal 
channels (88 total channels) • Selec- 
table 600 KHz repeater offset. 

595.00 list price. Cail for quote. 




— nn m — 

The NEW KENWOOD 
TS-700S 2m transceiver 

TS-700S has these new built- 
ins: • Digital readout, receiver pre- 
amp, VOX, semi-break-in and CW 
sidetone! Plus: • Solid-state con- 
struction • AC or DC capabifity • 4 
band (14.4 to 148 MHz) coverage • 11 
fixed channels • 600 KHz repeater 
offset. 

679.00 list price. Call for quote. 




DRAKE TR-33C 2m 
transceiver 

• 12 channel provision (2 supplied) 

• All FET front-end crystal filter for 
superb intermod. rejection • Ni-Cad 
ceils supplied • Built-in charger 

• Low power drain circuit on 
squelched receive • Lighted dial 
when using external power. 

229.00 list price. Gall for quote. 



Remember, you can call TOLL-FREE: 1-800-633-3410 in U.S.A. or call 1-800-292-8668 in 
Alabama for our low price quote. Store hours: 9:00 AM til 5:30 PM, Monday thru Friday. 

Long s Elecrtrcmics .. 





MAiL ORDERS; P.O. BOX 11347 BIRMINGHAM. AL 35202 • STREET ADDRESS: 3521 10TH AVENUE NORTH BIRMINGHAM. ALABAMA 35234 



139 



CaUlbUFiee 

1-800«633*3410 

for amplifiers 




YAESU FL-2100B 
linear amplifier 

TheFL-2100Bhas: • 1200 W PEP* In- 
put on SO-10 meters • Primary voltage 
change 1 17 to 234 VAC • Dual meters 
for plate current voltage • Adj. SWR 
meter • Individually tuned input coils 
on each band • Drive requirement: 30 
to 100 W. 

399.00 list price. Call for quote. 




DENTRON MLA-2500 
linear amplifier 

Features: • Continuous duty power 
supply • 160 thru 10 meters •2000- 
plus watts PEP on SSB« 1000 watts DC 
input on CW, RTTY, SSTV • Variable 
forced air coaling • 2 external-anode 
ceramic metal triodes operating in 
grounded grid • Covers MARS without 
modifications. 

799.50 list price. Call for quote. 




DENTRON MLA-1200 
linear amplifier 

The MLA-1200 is designed to fill the 
gap between your barefoot transceiver 
& a full 2 KW amplifier. • Single 
external-anode ceramic/metal triode 
yields.1 200 watts PEP on SSB & 1000 W 
DC on CW • Most other features same 
as MLA 2500 • AC power supply is list 
priced at 159.50. " DC power supply 
available. ■, ^ 

399.50 fist price. Call for quote. 




DRAKE L-4B 
linear amplifier 

The L-4B features: 2000 watts PEP on 
SSB. 1000 watts DC on CW, AM, & 
RTTY • High efficiency Class 8 
grounded grid circuit • Transmitting 
AGC • Broad-band tuned input 
• Directional wattmeter • RF neg. 
feedback • 2 taut-band suspension 
meters • Solid state power supply. 

895.00 list price. Call for quote. 




TPL 702 

2m RF amplifier 

TPL 702 has: • Solid-state • Linear 
switch (FM/SSB) • Broad band • In- 
put: 10W to 20W, output: SOW to 90W 
• Typical: lOW in/70W out • Frequen- 
cy coverage: 143 to 149 MHz. 7028 (fist 
price: 179.00) availabte, typical; 1W 
in/70W out. Input 1W to 5W, output: 
60W to SOW. 

149.00 list price. Call for quote. 




DRAKE AAMO 
2m power amplifier 

The AA-10 powerampfifier is made for 
use with the Drake TR-22C or any 
transceiver with up to t.8 watts output 
power, "lO dB power increase "At 
least 1 watts output @ 1 3.8 VDC • No 
relays — automatic transmit/receive 
switching • Compact. 

49.95 list price. Call for quote. 



Remember, you can call TOLL-FREE: 1-800-633-3410 in U.S.A. or call 1-800-292-8668 in 
Alabama for our low price quote. Store hours: 9:00 AM til 5:30 PM, Monday thru Friday. 

Longs Electronics . 



BflNXAMfBICflRD 




MAIL ORDERS: P O BOX 1 1347 BIRMINGHAM. AL 35202 • STREET ADDRESS: 3521 10TH AVENUE NORTH BiRMIMGHAM, ALABAMA 35234 
140 



CaUlbOFrae 
for micirvvhoiies 




KENWOOD MC-50 
desk microphone 

The MC-50 dynamic mike has been 
designed expressly for amateur radio 
operation. • Complete with PTT & 
LOCK switches • Easy conversion 
from HI to LOW impedance • Uni- 
directional • Mike plug on coil cord for 
instant hook-up to any Kenwood rig. 

39.95 list price. Call for quote. 



OVER 
50% 

^ OFF 

ELECTRO-VOICE 
719 desk microphone 

The 719 has two talk switch positions, 
grip-to-talk & push-to-talk. Features: 

• 80 to 7000 Hz frequency response 

• Ceramic generating element • High 
Z output impedance* Omnidirectional 
polar pattern. Simple instructions in- 
cluded for change of talk switch posi- 
tion. 

19.00 45.00 list price. 





SHURE 444 
adjustable desk mike 

The Shure 444 microphone head can 
b^e raised or lowered approx. 21/2" for 
the most comfortable talking position. 
PTT switch with optional focking 
feature. Omnidirectional.polar pattern, 
frequency response: 300 tb'8000 Hz. 

58.50 list price. Call for quote. 



YAESU YD-844 
desk microphone 

The YD-844 is designed for use with 
your Yaesu transceiver or transmitter. 
• Dynamic generating element • Fre- 
quency response: 350 to 2700 Hz • PTT 
switch & lock switch • 50 K ohm • Coil 
cord and microphone input plug for 
instant hook-up. 

29.00 list price. Call for quote. 




SHURE 414A 
compact hand mike 

The 414A is ideal for your portable 
transceiver, • One-fialf the size of most 
hand mikes • Omnidirection polar 
pattern • Frequency response: 400 to 
4000 Hz • High impedance • Output 
level 54.5 dB • 5y2 foot coil cord with 
input plug. 

45.50 list price. Call for quote. 




DRAKE 1525 EM 
hand microphone 

The 1525 EM is an auto-patch encoder 
& mike in one compact unit. • High 
accuracy IC tone generator, no fre- 
quency adjustments • Digitran® 
keyboard • Low output impedance 
• 4-pin plug & coiled cord allows use 
on most transceivers. 



49.95 



Call today for yours. 



Remember, you can call TOLL-FREE: 1-800-633-3410 in U.S.A. or call 1-800-292-8668 in 
Alabama for our low price quote. Store hours: 9:00 AM til 5:30 PM, Monday thru Friday. 

Long's Electronics . 



BflNKAMERICABn 




MAIL ORDERS: P.O BOX 11347 BIRMINGHAM, AL 35202 • STREET ADDRESS: 3521 10TH AVENUE NORTH BIRMINGHAM, ALABAMA 35234 



141 



CaUlbUFree 

1*800*633*34]0 

for antennas 




DENTRON all band HF 
doublet antenna 

This all band doublet or inverted anten- 
na covers 160 thru 10 meters. It has a 
total length of 130 ft. of 14 gauge 
stranded copper wire. Tuned & center 
fedthrulOOft. of470ohmPVCcovered 
transmission line. Assembly is com- 
plete. 

24.50 Call today for yours. 




HYGAIN TH3MK3 
HF 3-element beam 

Covers 10, 15, and 20 meters. 
Features: • Separate & matched Hy-Q 
traps for each band • Feeds with 52 
ohm coax • Up to 8 dB forward 
gain • 25 dB f ro nt-to-back 
ratio • Max. power input 1 KwonAM, 
2 Kw PEP • SWR less than 2:1 on all 
bands. 

199.95 list price. Call for quote. 




CUSHCRAFT ATB-34 
HF 4-element beam 

Catch DX instead of chasing DX with 
the ATB-34! • Covers 10, 15, and 20 
meters • High-Q coax traps rated for2 
Kw power. • Direct 52 ohm feed thru 1- 
1 balun • Forward gain: 7,5 dB, all 
bands • Front-to-back ratio: 30 
dB • Turn radius: 18' 9" • Wind sur- 
vival: 90 MPH. -. _ 

239.00 list price. Call for quote. 



ANTLER 
A-280 
2m mobile 
antenna 

The A-2B0 is as close 
to the ideal antenna as 
you can get. Fea- 
tures: • Precision tun- 
ed coil • 47" tapered 
17-7 stainless steel 
whip • VSWR: less 
than 1.3 • Certified 3 
dB gain • Magnetic 
mount has roof-top 
stability to withstand 
winds up to 100 MPH, 

39.95 list price. 
Call for quote. 





CUSHCRAFT A144-20T 
20-element twist antenna 

A144-20T has 10 elements horizontal & 
10 vertical, • Uses 2 Reddi Matched 
driven elements & simple coax phasing 
system to give horizontal, vertical, left 
or right circular, & axial 
polarization • Forward gain: 12.4 
dB • Front-to-back ratio: 22 
dB • Boom length: 12', Weight: 6 lbs. 

54.95 list price. Gall for quote. 



HUSTLER 4BTV 
10, 15, 20, & 40 
meter vertical 
HF antenna 

Band width at its 
broadest! • SWR 1.6 
to 1 at band edges 

• Solid 1 inch 
fiberglass trap forms 
for optimum electrical 
& mechanical stability 

• 1 W" aluminum wall 
sections* Optional 75" 
meter operation possi- 
ble • Feed with 50 ohm 
coax • Length: 21' 5", 
Weight: 15 lbs. 

79.95 list price. 
Call for quote. 



^^ 



I 



Remember, you can call TOLL-FREE: 1-800-633-3410 in U 

Alabama for our low price quote. Store hours; 9:00 AM til 



S.A. or call 1-800-292-8668 in 
5:30 PM, Monday thru Friday. 




Longs ElecrtrcMiics 



L9 




MAIL ORDERS P.O. BOX 11347 BIRMiNGHAM, AL 36202 • STREET ADDRESS" 3521 10TH AVENUE NORTH BIRMINGHAM, ALABAMA 35234 



142 



CaUlbUFree 

1*800*633*34]0 

frar accesscnries 




ESI POS-1220Z 
power supply 

This one really works! • 13.8 VDC 
regulated power supply • Current 
rating: 20 amps continuous, 30 amps 
surge • Fuse protected • LED power 
indicator • ON/OFF switch on front 
panel. This unit wil[ power a TR-7400A 
AND a KLIVI 160 watt 2m amplifier! 



69.95 



Call for yours today. 




NYE VIKJNG 
114-320-003 key 

This heavy-duty key is constructed on 
a heavy die-oast base. The hardware is 
nicl^el-plated. Has smooth adjustable 
bearings and heavy-duty coin silver 
contacts. Black wrinkle finished base, 
switch and Navy knob. 

10.60 Cad for yours today. 




BIRD Model 43 
Thruline® wattmeter 

The mode) 43 features: • 50 ohms 
nominal impedance • VSWR insertion 
with N connectors: 1.05 max. •Ac- 
curacy: plus or minus 5% of full scale 
• Shock mounted 30 microamp meter 
has 3 expanded scales of 25, 50, & 100 
to permit direct reading of full scale 
power from 100 milliwatts to 10,000 
watts • Plug-in elements are optional. 
2 to 30 MHz, 42.00. 25 to 1000 MHz, 
36.00. Other elements and accessories 
are available. "■■•-.., 

120.00 list price. Call for quote. 




NEW! 



The NEW DENTRON 
BIG DUMMY 

Now you can tune-up off the air with 
Dentron's Big Dummy foad. A full 
power dummy load, it has a flat SWR, 
full frequency coverage from 1.8 to 300 
MHz and a high grade industrial coof- 
ing oil furnished with the unit. Built to 
last! Fully assembled and warrantied. 
Help cut out the QRM factor now! 

29.50 Call for yours today. 




up— w 

DRAKE W-4 

RF directional wattmeter 

w-4 covers 2 thru 30 MHz • 2000 watts 
continuous duty power capabihty 

• Line impedance: 50 ohm resistive 

• VSWR insertion: no more than 1.05 to 
1 • Accuracy: plus or minus 5% of 
reading • 4 position switch selects: 
scale, forward, or reflected power. 

72.00 list price. Call for quote. 




MFJ 2BX 
super CW filter 

The MFJ CW fHter has: • Selectable 
band- width: 80, 110, 180 Hz • 60 dB 
down one octave from center frequen- 
cy of 750 Hz for 80 Hz BW • Reduces 
noise 15 dB • 9 V battery • Plugs in 
between receiver and phones • 8-pole 
active IC filter. 

29.95 Caii for yours today. 



Remember, you can call TOLL-FREE; 1-800-633-3410 in U.S.A. or call 1-800-292-8668 in 
Alabama for our low price quote. Store hours: 9:00 AM til 5:30 PM, Monday thru Friday. 

Long s Electronics . 



BankAmericard 




MAIL ORDERS: P.O. BOX 1 1347 BIRMINGHAM, AL 35202 • STREET ADDRESS 3521 1QTH AVENUE NORTH BIRMINGHAM. ALABAMA 35234 

143 



A. Sturko VSaNS 
Ft. Smith NWT 
Canada 



VE6 DXer 
Tells All ! 



-- what to do all winter 



During the fall of 1971, I 
took the opportunity 
to transfer from VE6 land to 
VE8 land to work in what 
was at that time the largest 
national park in the world, a 
total of 1 7,300 square miies 
of wilderness. 

Wood Buffalo Nationa! 
Park straddles the boundary 



between the Province of 
Alberta and the Northwest 
Territories. The park holds 
the distinction of having the 
largest herd of free-roaming 
bison in the world and the 
nesting site of the endangered 
whooping crane. 

We arrived in the small 
community of Fort Smith, 



N.W.T., with an approximate 
population of 2,500, on Janu- 
ary 12, 1972; it was -40° C. 
After traveling for 1400 miles 
on winter roads with a house 
cat and a back seat full of 
house plants which were stiiL. 
alive, it was a godsend to be 
at our new home. It was a 
land not very well known by 




From left to right: VE8NS, VE8LG and VE8RZ. 



the average North American, 
let alone the average radio 
ham. 

The area is located in the 
northwest extremity of the 
Great Northern Plains, well 
within the Boreal Forest 
Region. It is a land of sharp 
contrasts, 24-hour daylight, a 
semiarid region with 10-12 
inches of precipitation per 
year, and hordes of mosqui- 
toes and black flies that could 
drive a human being crazy in 
hours. It's a land of northern 
lights, -50** C, dog teams, 
hunting and trapping still a 
way of life, short winter days, 
and ice crystals to brighten 
the way. 

At the time of my arrival, 
Terry Keime VE80K was an 
avid DXer. I enjoyed the 
bands from this QTH. VE8s 
were in demand, which made 
DXing interesting. With the 
eventuaJ arrival of VE800 
and VE8RO on the same 
block, would you believe we 
had QRM alley in VE8 land? 
There it was in full bioom. i 
checked out the ham popula- 
tion, and, according to the 
list, there were =52 licensed 
operators, with approxi- 
mately 20 active hams. And 
three of them were on the 
■ same block. 

Time was the pacifier untii 
the opportunity presented 
itself — a move to'the other 
side of town. Now was my 
chance to get away from rf 
burns on everything 1 
touched. 

Once we were settled in, 
with beds on the floor and 
boxes piled everywhere, my 
thoughts turned towards an 
antenna structure. The days 
were becoming shorter and 
colder rapidly. The concrete 
base was poured by candle- 
light, and prayers were said 
for a warm weekend, just one 
good weekend to put up the 
structure. God was willing, 
and the antenna was on top 
with hours to spare. The fol- 
lowing week proved how 
unpredictable the weather 
can be — snow and wind with 
minus 10° C. (It's a smug 
feeling to have all the outside 
work done.) The antenna 
performed as expected, 



144 



[oaded well, and all that was 
left was to pile up the DX. 

But my rule of the roost 
was soon to be shattered with 
the arrival of an old friend, 
Gerry VE8LG, a graduate 
from an electronics school 
and now a radio inspector 
with the Department of Com- 
munications in Fort Smith, 
N.W.T. The die was cast. 
Gerry was moving in next 
door! How is this possible 
with 2 million square miles of 
VE8 land? Two DXers 
squeezed into an area of 
1,000 square feet made me 
wonder at the mathematical 
odds and shake my head. 

Once the initial shock was 
over and I became somewhat 
rational, we discussed old 
times, invariably getting 
around to amateur radio. A 
plot was formed. VE8LG had 
intentions of purchasing a 
Wilson 520 (for the unini- 
tiated, the Wilson 420 has 4 
elements on a 30' boom; the 
520 has 5 elements on a 40' 
boom) and a self-supporting 
64' tower to support the 
beam (with a Ham II rotator 
to turn it}. The entire con- 
struction procedure went well 
and 5 elements were soon up. 

The area of residence of 
VE8NS and VE8LG was 
taking on an air of space age 
mystery, in the space of 100', 
two 64' towers and one 40' 
tower, supporting a Wilson 
520, 420, and 415, and an 
inverted vee for 40 and 80, 
were serving two amateur 
radio stations — the VE8LG 
Kenwood twins and the 
VESNS TR-3 Drake line. We 
were rather amused whenever 
people or vehicles passed tay. 
Invariably they slowed down 
to look at all the flying 
aluminum and shake their 
heads, with quizzical loolss as 
if to say, "What is going on 
here?" Thank goodness for 
rather nonstringent town 
bylaws, or we would not have 
been allowed to proceed. 

Tests were started imme- 
diately, and, as expected, the 
beam performed according to 
specifications. We decided to 
hook both transmission lines 
to an antenna switch. Since 




VE8NS' beam was only 50' 
away, it presented no prob- 
lem to extend a coax a little 
bit. 

The results from the 
experiment were confusing. 
With both beams pointing to 
Europe, transmitted signal 
strengths were basically the 
same in all cases. However, on 
received signals the 520 beam 
registered as much as 3 
S-units over the 420 beam. In 
some cases we were unable to 
copy signals on the 420 beam 
which were an S2 on the 520 
beam. 

With beams pointing 
toward ZL-VK land, again we 
were in for a surprise, ZLs 
were consistently giving 
better reports from the 420 
beam than from the 520 
beam, by as much as 1 S-unit. 
At no time were the trans- 
mitted signals better on the 
520 beam. Received signals 
were better by as much as 3 
S-units on the 520 beam. 
Perhaps further experi.rients 
will be carried out lo deter- 
mine whether adjustments to 
both beams may change the 
present pattern. However, the 
experiments were a lot of 
fun. Maybe the old adage, 
"the bigger the better," does 
not hold true in this case. 

It is impossible to work on 
the same band. However, 



VESNS contemplating the job. 

with 15m openings, VESNS is 
able to operate with mini- 
mum QRM. If all the bands 
are out, then work is con- 
tinued on the 2 accu-keyers, 
with one working and one 
more to go. But that's 
another story. 

A matter of interest to 
hams looking for contacts in 



zone 1 VE8 land - VE8RZ, 
VESLG, VE80V and VESNS 
are active on 20, both CW 
and SSB. VESNS is the QSL 
bureau manager for VE8 
land. 

A thought just occurred to 
me, I haven't. noticed any rf 
burns at this QTH. Could it 
be there never were any? ■ 




From front to back: the Wilson 520, the Wilson 415, and the 
Wilson 420. 



145 



Tufts Radio Electronics • 209 Mystic Avenue • IVIedford MA 02155 • {617| 395-8280 



PROFESSIONAL HEADPHONES 
& HEADSETS 



BOOM WIIC HEADSETS 

For the ultimate in communications convenience and efficiency select a boom mic iieadset. Long-tjme favorites of professional 
communtcations, boom mic headsets allow more personal mobility while always keeping the mic properly positioned for -fast, precise voice 
transmission. Boom microphones are completely adjustable to allow perfect positioning. And, boom m,ic headsets leave botti hands free to 
perform other tasks. 

AH models are supplied with "close-talkjng" microphones to limit ambient noise pick-up and provide superior intelligibility. Sach model has 
a convenient, inline push-to-tal k switch, which can be wired for either push-to-talk relay control or mic circuit interrupt for voice operated 
transmitters. The switch may be used as a momentary push-button or it can be locked in the down position. All models have tough, flexible, 
a foot cords which are stripped and tinned, unterminated. Communication grey with black trim. 




MOD6LC610 





Dealer Programs 
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MODEL CM-IZIO 




MODEL CM-taZOS 



MODEL CM-eiO 



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MODEL C-61 Economical, dual receiver 
magnetic headphone. Delivers clear re- 
ception. Lightweight and comfortable yet 
ruggedly constructed for daily use. Ear- 
cushions seal out distracting noise and 
are removable for cleaning. Price: $9.95 
MODELSWL-610 Similarto Model C-610 
but with 2000 ohm impedance. Ideal lor 
shortwave receivers requiring high im- 
pedance headphones. Price: $9.95 
MODEL C-1Z10 Medium priced, dual re- 
ceiver dynamic headphone. Precise 
sound reproduction. Deluxe foam-filled 
earcushlons are extremely comfortable 
"tor those long sessions. The removable 
cushions reduce ambient noise penetra- 
tion and concentrate signal strength. 
Great for noisy environments or for dig- 
ging oul weat< signals. Prices $28.30 

MODEL C-1320 Our linest communica- 
tions headphone. Audiometric-type dual 
dynamic receivers assure the ultimate in 
receptjon and performance stability. Ex- 
tremely sensitive receivers provide high 
output levels even from weak signals. 
Luxurious foam filled circumaural ear- 
cushions are removable tor cleaning. 
Price: S37 .90 



DUAL MUFF HEADPHONES ... _.. 

The foHowing headphones offer outstanding sound quality and superb comfort for long term wearing. All the nnodels have circumaural 
earcushlons to seal out distracting ambient no ise and concentrate the signal at your ear. Foam flHed vinyl earcushlons on Models 0-1210 and 
C-1320 add an extra margin of comfort. Adiustable headbands and self-aligning earcups assure proper fit. All models are equipped with a 
five foot cord termirtating In a standard .250" diameter phone plug an<i have 3.2 to 20 Ohm impedance. Communication grey with black 
trim. 

MODEL CIVi-610 Lightweight, dual receiver 
magnetic headphone (similar to ^^odel 
C-610). Ceramic boom microphone with -SI 
dB output. Can be used with any mobile or 
base station with high ^ mic input and 3.2 
to 20 ohm audio output. Price: 542,30. 

MODEL CM-1320 Deluxe dual receiver 
dynamic headphone with audiometric-type 
headphone elements (similar to Model 
C-1320). Ceramic boom nnfcrophone with 
51 dB output- For use with any mobile or 
base station requiring high impedance mic 
input and 3.2 to 20 ohm audio output. 
Price; $68.30. 

MODEL CM-1210 Rugged, reliable, dual 
receiver dynamic headphone (similar to 
Model C-1210), Ceramic boom microphone 
with -51 dB output. For use with any 
mobile or base station with high Z input and 
3.2 to 20 ohm audio output. Price: S56.90. 

MODEL CM-1320S Deluxe single receiver 
dynamic headphone with audiometric-type 
headphone element (similar to ft/lodel 
C-1320). Ceramic boom microphone with 
-51 dB output. For use with any mobile or 
base station requiring high impedance mic 
input and 3.2 to 20 ohm audio output. 
Price: $54.50. 



MODEL 


C-6SD 


SWL-61D 


CI210 


i;i320 


CIViElD 


i;ivi-f2io 


M1320 


CM-1320S 


HeadphcneSensi!:VJly 
Rel 0002 Dynes-cm' 
S 1 mW itipji. : kH? 


■OS-IB SPL 


IDSdBSPL 
^[18 


IQ3cB3PL 
^dB 


IG5d6SPL 


:03dBSP;-^ 
*6dB 


lOJdBSPL 


lOSdBSPL 
i5aB 


IGSdBSPL 
•SdB 


Hsadphonefrequtncy 
Response juseatilel 


40 
15,000 Hz 


40 
15,000 Hi 


20- 
20,000 Hi 


20-- 
20,000 Wi 


40- 

15,000 Hz 


20- 
20.000 Hz 


20- 
20.000 Hz 


20- 
20,000 Hz 


Headphone 
Impedance 


3.2- 
20 ohms 


2000 ohms 


3,2- 

20 ohms 


3,2- 

20 ohms 


3.2 
20 ohms 


3-2 
20 ohms 


3,2- 
20 ohms 


3,2- 
20 ohms 


Mlciopnone 
Frequsncy 
Response 






" 


^ 


50- 
aOOO Hz 


50- 
8000 Hz 


50- 
8000 Hz 


50- 
aOOQHz 


Mic:ophcine 
Ifrpedance 


- 




- 


- 


High 


High 


High 


High 


Microphone 

Sensitivity 
Below 1 voltymicrnbai 

at UHz 










-51dB 
±5dB 


-51ilB 
±5iJB 


- 51tIB 
i5dB 


51dB 
:*:5dB 


Cortl 


6- 


5- 


5- 


5- 


e 

i2 4ri 


s- 


8' 


e- 


Plug 


260- liis 


250- dia 


260- Cia 


260- dia 


uniei- 
minated 


unier- 
nnated 


unier- 
mmated 


unler- 
minaied 


Gfoss Weight 


122781 


8 or. 


12 oz. 
134181 


15 oz. 
112681 


12 az- 


15oz 


18 oz. 
(Bll8> 


l2oz. 
|341g) 


Catalog Number 


B1B30-063 


61B30-0i)2 


61210-031 


B132O-012 


61630064 


61200-058 


61320-013 


61320-015 



Tufts Radio Electronics • 209 Mystic Avenue • Medford MA 02155 • {617} 395-8280 



Tufts Radio Electronics • 209 Mystic Avenue • Medford MA 02155 • (617) 395-8280 



SST T-1 RANDOM WIRE ANTENNA TUNER 



1^ 



AU band operation (160-10 meters) with 
most any random length wire, 200 Watt 
power capabilits'. Ideal foi portable or home 
operation. A must for Field Day. Si'ze: 2 x 
4-1/4 X 2-3/8, Built-in neon tune-up indica- 
tor. Guaranteed for 90 days. Compact — 
easv to use. Only $29.95. 



Model 







Model 
200 V 



CES Touch Tone Pads 

• Model 200V — acoustic coupling. S59.95 

• Model 210 — for mounting on walkies or 
hand-helds. $5435 

• Model 220 — CES can now offer you a 
TOUCH TONE back for Standard Commun- 
ications hand-held radios. This is the com- 
plete back assembly with the TOUCH 
TONE encoder mounted and ready to plug 
into the private channel connector. Also 
included is a LED tone generator indicator 
and an external tone deviation adjustment. 
$74.95. 



talk 





ASTATIC 

MICEOPHON ES 



SILVER EAGLE - $69.95 

T-UG8-D104, transistorized $48.60 

T-UG9-D104, "Golden Eagle," transistorized $95.40 
T-UG9-D104, "SUvet Eagle," transistorized . $69.95 
UG-DJ.04, ceramic or crystal $42.60 



jW7#for an Economy Price? -^ 
THAT'S RIGHT! 
introducing the ECONO-LINE 

IWadel input Output Typical Froquoncv 

703 5 ?OW 50-90W lO in/70 out -L-da-MgMHz 
7023 1 -IW EOSOW 1io/70 0LH l.iG-l-igMHj 



S 139.00 
£169.00 



Now get TPL COMMUNICATIONS 
quality Sind reliability at an economy 
pr^ce. The nevj Econo-Lme gives you 
everything that you've come lo expect 
from TPL at a real cost reduction. The 
latest mechanical and electronic construc- 
tion techniques combine to make the 
EconoLine your best ampi ifier value. 
Unique broad-band circuitry requ ires no 
tuning throughout the entire 2-meTer band 
and adjacent MARS channels. See these 
great new additions to the TPL COMMUN- 
ICATIONS product line at your favorite 
amateur radio dealer. 

For pr\ces and specifications please write 
for our Amateur Products Summary^ FCC 
type accepted power amplifiers also avail- 
able. Please call or write for a copy of 
TPL's Commercial Products Summary. 



$43.95 
Kit 

A LOT of antenna in a LITTLE space 
New Slinky® dipole* with helical 
loading radiates a good signal at 1/10 
wavelength long! 

•paieni No. 3,858.210 




i-TQd »»■ U^l :ttL 










* Tflisel&cirica%smaiieC/75,-40, &MiTi£ter arrennaoperaies 
3[anyi*r:9ihffom2*io7{)feei ■ mitxii'a balunor liarsmaich 
needed > portable— ^recti & siarcs ^n minuies • small 
enOughtofilinaniCOl aparrrnent * lull ^cgal power ■ IbwSi^R 
OverCOmplelBA0/75. 40. & 20 meter bands * muchlnweraimo- 
spheric noise pickup ihan a vertical and reeds rK> (acMals > kii 
includes a pair al ■tMcial1y-inad« 4Hrtch dia. by 4-incri lon^ 
cojht, coniainmg 336 te«l of radiating conductor, balun, Ml ft. 
■ flGM/y coax. PL259 connector. nylor» rope A inslruclion fnari- 
l^^\ * no*in use by US Dept. ol Slate. US Army, radio sr^hools. 
plus IhousendS ol harps the world over. 



r-'; ■■-■■ 



FT-301 D 




FT- 1 01 E TRANSCE tVER 



FT 301 
FP301 DIG 
FP301 

FP301 cm 

FRG-7 
QTR-24 
FT 101-e 
160-1 OM 
FT-101EE 
160-1 OM 

FT- 1 01 ex 

16Q.10M 

FL-2100B 

FTV-650E 

FTV-250 

FV-IOIB 

SP-101E 

SP-t01PB 

YO-10D 

YD-344 

FA-9 

MMB-1 

RFP 102 

XF 30C 

FR-101S 

SOLID STATE 

Ffi 101 DIG 

SOLID STATE 

FT 301 s 

FT 301 S 



1 60 M-10M Transceiver - 200 WPEP $769 
160M-1QM Transceiver - 200 WPEP 93B 
AC Power Supply 125 

AC P.S. w/Clock and CW ID 209 

General Gov. Synthesiijed Receiver 299 
Yaesu World Ciock 30 



Accessories: 
FC 6 
FC 2 
FM-1 



XCVR W/Processor 

XCVR W/O Processor 

XCVR W/O Prooessar 
AC Onlv, Less Mike 
Linear Amplifier 
6IV1 Transverter 
2M Transverter 
external VFO 
Speaker 
Speaker/Patch 
Monitor Scope 
Dynamic Base Mike 
Cooling Fan 
Mobile Mount 
RF Speech Processor 
GOO Hz CW Filter 

1tiO-2M/SW RCVR 

160-2M/SW RCVR 
16Q-10M40WPEP 
lea-IOM MWPEP Digital 



729 
649 



589 

399 

199 

199 

109 

22 

59 

199 

29 

15 

19 

79 

40 

489 

599 
559 
785 



6M Converter 
2M Converter 
FM Detector 
Aux/SW Crystals 
AM-Wide Filter 
600 Hz CW Filter 
FM Filter 
Speaker 



XF-30B 

XF 30C 

XF-30D 

SP-101B 

FL-101 

SOLID STATE 160 lOM 

TRANSMITTER 

Accessories: 

RFP-101 RF Speech Processor 

MONITOR/TEST EQUIPMENT 

YC 500 J _ ^ 500 MH3 ;iO PPMj 

Counter 
YC 5O0 S 50G MHz (1 'PMi 

Counter 
YC 500 E 500 MHz 10.03 PPMI 

CoLinter 
YO-100 Monitor Scope 

YP-15D Dummy Load/ Watt Meter 

YC-601 Digital Readout 

1101/401 series) 
VHP FM & SSBTRANSCEIVERS 
FT-620B 6M AM/CW/SSB 

FT-221 2M AM/FM/CW/SSB 

. Accessories: 
WMB-4 IWobile Mount 

(FT-e20B. FT-221) 



24 
25 
20 
5 
40 
40 
49 
22 



249 
339 



69 
169 



366 
629 



TUFTS 



Radio Electronics 

209 Mystic Avenue _ 
Medford MA 02155 
(617) 395-8280 

FREE Gift With 
Everij Order! 



Name- 



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Citv 

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Tufts Radio Electronics • 209 Mystic Avenue • Medford MA 02155 • (617) 395-8280 



Tufts Radio Electronics • 209 Mystic Avenue • Medford MA 02155 • (617) 395-8280 



HHM RRDIQ/ 

MOBILE 

COMMUNICRTION5 



O 



THOMSON-CSF 



NPC 





ELECTRONICS 




MODEL 


NET PRICE 


103R 


$39.95 


12V4 


$19.95 


»13 HM4 


$41 .95 


600 


$20.50 


104R 


$49.95 


102 


$24.95 


12/115 


$69.95 


612 


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108RA 


$79.95 


107 


$28.95 


108RM 


$99.95 


12 HM4 


$29.95 


109R 


$149.95 






ALSO! Available as 
13 HM AiMith built-in 
laudspeak^T, 

O^J'.3!Jl Vcllage 

ConfmuOusGurertt 

Hippte/NiQise 



MODEL t2HM4 

NPC2.5Arr.c Begu+aTed Power Suppiv 
Solid Siale, Sho^i Circuit f:-OTecTe(l- 

Low cast reguiaied pow&r supply 
quietly converts ItS volts AC to 
13.5 volls DC i200 millJvolts. 
1.5 amps cofiijjiuDus, 2.5 amps 
reg. Ideally suited for operaiirwi 
mobile CB transceivers in yosF 
home or otiice base station. 



TYPICAL 
13 5 H^ 5VDC 
1.5 AiTip 
2.5 Amjj 
5 irV RMS 



Case: 3" (Fiji's' (Wj x 5^'■ ' '.D;- Sniopirg rteighf: 3 lbs. 



MODEL 107 



IMPC 4 Amp Power 

■ Supply, G Arnp Max. 

Soiid State. Overload 

Protected 



_0 



Functions silerlly ir converting 115 volts AC to 12 voHs DC 4 amps 
continuous. 6 amps max. Enables anyont to enjoy CB radiu, ca: B-Stack 
cart-'idge. cassene player or car radio :r. a home or otiice. 



.Ccr.^JnvjOuisCLiirpn! (Full Losci 
O jlpu I Voltage ■(Nc Load) 
Ojipui Vo'iage (Full Load) 
FiHeririg Capacrtof 
Pippie (Full Load} 
Shcri Circuit Fmlpction 



J Arrp 
56 VmsTc 
12 Vfnjn 
:0,CCG uf 
5 V RMS 
Thermal Breahe/ 



l>OWER SUPPLY 



REGULATEH o>, 




MODEL 103R 

NPC 4 Amp R»gu"at&d 
Po^^■er Supply. 
Solid SiiiTe. Dual 
Ove/toad Protection. 



CorvertsllSvoUs AC to 13.6 volts DC ri-20D mitltvolis, Handl&s 2.5 
amps continuous and 4 amps ma>(. ideally suited tot applications 
where no hum and DC stability are important sucli as CB Iransmission, 
small Nam radio i ran srni Iter, and tiigh quality eiyhl-track car stereos. 
Can also be used lo tricWe- charge 12 voh car batlerics. 

TYPICAL r.iAJtr.iuw 

^56 ^.?VOC V-} 6 ■ 3V^C 

2 mV RMS i r.;F.7,:S 

£.5 AtriD 



C^e:3"iH| bt4ii |W;x5W-(D). Snipping Weigni: 5 lbs. 



0;jTpuI Vo]!ii&e 
Lme/Loaa R&^uiaiiori 
Rhpple'WolSG 
Tiansian: Response 
Currem Cominucus 
CyrftniUmil 
C^J^^er^tFo[dt^3C!^ 

C35e-3'[H)x-; .■■^v/,. 



1 Arrtp 
iD}- Snippng Weigh! ^ Sb. 




MODEL 109R 



MODEL 108RM 

NPC \2 Amp Regulared 

Power Supptv- 

Solid State. 

3-Wav Protected. 

Cnjrrent Meter, 



This heavy duty unit quietly converts 115 volts AC to 13.6 volts DC 
±200 miilivoUs. 6 amps continuous. 12 amps max. All solid state. 
Features dual current overload and overvoitage protection, ideally 
suited lo; operating mobile t^am radio 2 mzler AM-FKVESS trans- 
ceiweis in your home or office. Can also be usEd Ic trJckle-cnaige 13 
volt car batte-ies 

(.MAXIMUM 

13 6 ^3VDC 

£CmV 

mV RMS 







TYPJC.il 


OuTp=>; Voilage 




13.6 : ?VDC 


Line/Load Re^ulahon 


?GmV 


Rippte/S>3 SE 




2mVRMS 


"tans enr Response 




20 uSec 


Curreni Ccr-irLin-js 




E Amp 


Cinrent Lii-nil 




12 Amp 


Current FolCback 




2 5 Amp 


OvervoHagc Piolecl 


on 


14,5 V 


Case:J'//(Hl«7'.r 


(W} X 5'^ 


(Dl. Shipg.iq, 



ALSO AVAILABLE AS MODEL lOBRA 
WITHOUT METER AND OVERVOLTAGE 
PROTECTION. 



NPC 26 Amp Regulated Power Supply, 4-Wev Protected. . 
Output Voltage and Current IVteters. 

Extra heavy-duty unil quietly converts 115 volts AC to 13.6 volts DC i 200 
millivolts. 10 amps continuous, 25 amps max, ftH solid state. Features 
dual current overload, overvoHage and thermal pfolection. ideally suited 
for operating mobile Ham radio and linear amplilier in your h^mft or office. 
Excellffit benth pnwer supply 5or tesling and servicing of mobile commL- 
nicationseqtiLom&cI 



Ouipjl Vol^&ge 
Lire.' Load Peculatiori 
flipoleNoiSe " 
TransLsr; R^s::,:ir5c 
Cjrf-ent Co--', nuo-js 
Curien: Lirr.ii 
Ov^Tvoliage Proit^c'.ian 
Thermal Ovariaad 
Case: 4H' (H) f. 9" (W) x. SW 



13.6 i 2VDC 

50 mV 

6 mV RWS 

lljArr-p 
26 Amp 

1^ 5 V 1 

lao^F 

;D). Snipping Weight: 15 Jbs. 



■.3_6 1 3V|>C 
IOdiVRMS 



MODEL 104R 

NPC e Amp Power Supply 
Regulated. 
Sotid State. Dual 
Overlcati Pratectiorj- 

Conmts 115 volts AC to 13.6 volts 
DC 4 200 fPillitOllE- Handles 4 
amps cn^tinusus and 6 amps ma?.. 
■-^ Weatty suitf-d lor appiicationa vj^t't 
excellent DC staPilily is important, sucn 3s CB iransmtssicn. small Ham 
radio I'afisminer. and high quality eight-l;ack cs- stereos. Can oe useo to 
lic'nle-cJiar^c' l? volt car batieries. 

s.;«xiii9u;j.- TYP z-'. _ 

6 ±2V0C 1 Jt>,: VDC 




Ou^ui Vollage 
Line/Loaff Regiilal on 
Ripple/ Ncise 
Transieit feSpCnSe 
Current Contifiuoiis 
Current Limit 
Curr«n( FoldbHcft 
Ca3e:3V(Kix5'.."(W)x6'- 



£CmV 

2 mV RWS 

2C tiSec 



SrrVFVS 




MODEL 12V4 

NPC 1,75 ArThp 
Power Supply. 
3 Amp Max. 

Functions silently m conven- 

ipg 115 vDlls AC 10 12 volts 

DC. ioealiv Suited *0[ rrosi 

applications u-vcltiCSittg B-track stereo, burglar alarirt. caj radio and 

cassette tape player within powej^ rating. 

Confinyoia^ Current (Fufl Load! 
OulpJl Vo ' ■^^(No LojO) 
OjJip"Jt-l/o ■ .^--(FliI' Load"! 
Filleting C ilor 

HpplelFii.i -_-3ll) 
Etion CirttiJt P?OieC!i jn 



■.75 Amp 
^6 V rra.^ 
12 Vmin 
£.000 uF 

ivnws 

Thefrnal Breaker 



2 Amp 

(Dl Sflipping Weight: e lbs. 



!! 3"llri)« 4" iW] xS".i (D). Shippir^Q ipV^iorn J Ihs. 



MODEL 10S 

WPC 2,5 Amp 

Power Supply. 

4 Amp Max. Solid Stale. 

OverlOiid Protected. 

FunclioriS 5iler!;y in wnvtn- 
mg 115 veils AC 10 12-votls 
DC. 2.5 amiJS CMllinuoifi. i aups m55f. Enaaes anyone la enjoy CB 
radio, car B4rack cartridge, cassette lape player o- car rsdio 'in s hoT.e 
c cffice. 

Conlin.ja J5 CurnenT ( F ull Lc^tJ) 2.5 A Tip 

Oulp^:Vo:i2ge(NoLoa<J) - levmax 

Oulp jl VoKage iFul' Load) 'EVmin 

Fiilering Capaciior 
Pippre;Fuif Loao] 
Siiori Circuit Prolecirtin 




S.CWvF 
.sv RMS 
rnerma! Breaker 



Case:3"(H)x4^l"(W) « 



■[DJ, snipping Weigrit .1 lbs 




'General Multi-purpose V-O-Ms 
*Drop Resistant 

• Hand Size 

• Model 310V.O-M 
•Type 3. 



1. Drop-resistant, hand-size V-O-M with high-impact thermoplastic 
case. 

2. 20,000 Ohms per volt DC and 5,000 Ohms per volt AC; diode 
overload protection with fused Rxl Ohms range. 

3. Single range switch; direct reading AC Amp range to facilitate 
clamp-on AC Ammeter usage. 

RANGES 
DC Volts: 0-3-12-60-300,1,200 (20,000 Ohms per Volt). 



Dealer Programs 
NOW Available 



AC Volts; 0-3-12-60-300-1,200 (5,000 Ohms per Volt). 

Ohms: 0-20fc-200k-2M S2-20IV1 n (200 Ohm center scale on low 

range!. 

DC Microamperes: 0-600 at 250 mV. 

DC Miiliamperes: 0-6-60-600 at 250 mV. 

Accuracy: ± 3% DC; +4% AC; (full scale). 

Scale Length: 2-1/8". 

Meter: Self-shielded; diode overload protected; spring backed jewels. 

Case: Molded, black, high impact thermoplastic with slide latch 

cover for access to batteries and fuse, 2-3/4" w x 1-5/16" d x 4-1/4" 

h. 

Batteries: NEDA 15V 220 (1), 1%V 910F (1): Complete with 42" 

leads, alligator clips, batteries and instruction manual. Shpg. Wt. 2 

lt>s. 

Model 310 Cat. No. 3018 $53.00 



Tufts Radio Electronics • 209 Mystic Avenue • Medford IVIA 02155 • (617) 395-8280 



Tufts Radio Electronics ♦ 209 Mystic Avenue • IVIedford MA 02155 • (677) 395-8280 




nnr 



TEM-TEC 



Dealer Programs 
NOW Available 



AMPLI- 
^05 



ARGONAUT. MODEL 509 

Cavers oil Amateur bartiis 10-30 meters. 
3 MHz crystal filter. 2.E kH? hanrl'-vidth. 1.7 
iharje factor @ 6/50 dB points. Po'.ver 
refjLiied 12-15 VDC S> 1 50 mA receive, 800 
n^A rraffsmit at r^tea" outpi.ii. Construction: 
aluntin^i^n chassis, lop 9n:1 rront panel, 
molded plssjic er^d patwis. Cream front 
pi3nel, walriut vinyl top antJ epti trim. Size: 
HWD 4V.." X 13- X y. Weighi 6 lbs. 

LINEAR AMPLIFIER, fl/IODEL 405 

Covers ail Amateur bands 1 0-SO meters. 
60 wau5 output power, continuous sine 



^%'gve. RF '/w-attmeter. SV^'R meter. Power 
renuired 12-15 VDC @ 3 A, max. Construe 
tior\: aluminum cftassis. top and front p3nel. 
molded plastic side oanels. Cream 'ronl 
panei, wijlrui vinyl top and end trim. Size: 
HVJD 1'V X 1" n S". Wsi^hi 2V; lbs 

Argonaut, Model 509 $359.00 

Linear Amplifier, Model 405 . 159.00 
Power Supply, Model 251 
(Will power both units) .... 
Power Supply, Model 21 
(Will power Argonaut only) 




The new ultra-modem Mly solid-state TRITON makes operating easier 
and a lot more fun, without the limitations of vacuum titbes. 

For one thing, you can cJiange bands with the flick of a switch and no danger 
of off-resonance damage. Aod no deterioration of performance witli age. 

But that's not all. A superlative 8-pole i-f filter and less than 2% 
audio distortion, transmitting and receiving, makes it the smoothest 
and deanest signal on the air. 

The TRITON W specifications are impeccable. For selectivity, stability and 
receiver sensitivity. And it has features such as ;uH CW break-in, pre- 
selectable .ALC, off-set tuning, separate AC power supply, 13 VDC operation, 
perfectly shaped CW wave form, built-in SWR bridge and on and on. 

For new standards of SSB and CW coinEQumcation, write for full details 
or talk it over with your TEN-TEC dealer. We'd bie to teU you why "Tliey 



Don't Make 'Em Like They Used To" makes Ham Radio even more fan. 
TRITON IV se99,0O 



ACCESSORIES: 

Mottel 240 One-Sixty Convetter....S 97.00 

Model Sf4 Digital Readout _.. 19T.0O 



Model 24i OV Filtef 535.00 

Model 249 Noise Bbnker 29.00 

Model 252G Power Sypplv 109.00 

Model 262G Power Suppljv'VO.X . . 139.00 



KR20-A ELECTRONIC KEYER 
A fine instrument fo£ all-ajound high perfor- 
mance electronic keying. Paddle actuation 
force is factory adjusted for rythmic smooth 
keying. Contact atijustments on front. 
WeiEhtJng factor factory set for optimum 
smoothness and articulation. Over-tide 
"straigtit key*' conveniently located for 
emphasis, QRS scndittg or tune-up. Reed 
relay otitput. Side-tone generator with 
adjustable level. Self -completing, characters. 
Plug-in circuit board. For 117 V.'^.C, 50-60 
Hz or C-14 VDC. Finished in cream and 
walnut vinyl. Price $69.50 

KJt5-A ELECTROKIC KEYER 
Similar to KR20-.'^ but without side-tone 
oscillator or AC pow-cr stipply. Ideal for 
portable, mobile or fixed station. .^ great 
value that will gi^-e years of troublefree 
service. Housed in an attracti^'e case with 
cream front, walnut vinyl top. For 6-14 
VDC operation. Price S39.50 

KRl-.\ DELUXE DUAL PADDLE 

Paddle assembly is that used in the KR50, 
hotised in an attractive formed aluminum 
case. Price *35.00 

KR2-A SINGLE LEVER PADDLE 

For keying conventiorral "TO" or discrete 



character keyevs, as used in the KR20-.A.. 
Price $17.00 

KR50 ELECTRONIC KEYER 

A completely automatic electronic keyer 
fully adjustable to yotir operating style and 
preference, speed, touch and weithtittg, the 
ratio of the length of dits and dabs to the 
space betweett them. Self-controUed keyer 
to transmit your thoughts clearly, articu- 
lately and almost effortless. The jambie 
(squeeze) feature allows the insertion of dits 
and dabs with perfect timing. 

.An automatic weighting system provides 
increased character to space ratio at slower 
speeds, decreasing as the speed is increased, 
keeping the balance between smoothness at 
low speeds and easy to copy higher speed. 
High intelligibility and rythmic transmission 
is maintained at all speeds, automatically. 

Memories provided for both dits and 
dahs but either n^ay be defeated by switches 
on the rear panel. Thus, the KR50 may be 
operated as a full iambic (squeeze) keyer, 
with a single ineinory or as a conventiotial 
type keyer. All characters are sclf-complet- 
mg. Price $1 10.00 

SPECIFICATIONS 

Speed Range: 6-50 w,p,tn, 
Weighting Ratio Range: 30% to 150?i> of 
classical dit length. 



Memories: Dit and dah. Individual defeat 

switches. 
Paddle Actuation Force: 5-50 gms. 
Power Source: 117'VAC, 50-60 Hz, 6-14 

VDC. 
Finish; Cream front, walnut vinyl top and 

side panel trim. 
Output: Reed relay. Contact rating ,15 VA, 

400 V. max. 
Paddles: Torque drive with ball bearing 

pivo t. 
Side-tone: 500 Hz tone. 




cushcroft 



4 ELEMENT BEAM 



From one package you receivG every component to quicklv and easily assemble your 
b sarin, ATB-S-i's rugged construction, f ul 1 power handling capabil ity, broad band 
coverage, and four active elements will give you superior performance on all three bands. 
Our new coaxial traps are very high Q, resulting in ejftremeJy low ohmic losses and | 
tonger full performance elements. They are rated for 2KW power handling. Feed Js direct 
62 ohm through the 1-1 balun, supplied at no extra cost. 






■ ir J> «>-'»flr ^>^*f 






Now You Can Receive The Weak Signals With The ALL NEW 



Model PT-2 is a continuous tuning 6! 60 
meter Pre-,.\nip specifJcaDv designed for 
uw wilh a Iransceiver. The 1*7-2 coih- 
bineh the fealureE of the well-known PT 
with new Bophieticated control ciixultry 
thijt |>eni)itJ it to be added to virtii3lly 
any Ir-inaccivcr with No modification. 
Mo BtrioiiB ham can E>e without one. 



• Improves Ben3iliii"ily and signal -to- noise ratio. 

• Boosts signals np to 26 db. 

• For.A.Mor ySB. 

• Bypasses itself automatii-ally when (he transceiver is I m nam it ting. 

• FET amplifitr gives superior cross modulation protection. 

• Advanced solid-state circuitry. 

• Simple to install. 

• Improves immunity to transceiver front-end overload by uee of its built-in attenuator, 

• Provides njastftr powcf controJ for station e(|uipmKnl. 



Tufts Radio Electronics • 209 Mystic Avenue • IVIedford MA 02155 



Tufts Radio Electronics • 209 Mystic Avenue • Medford MA 02155 • (617) 395-8280 



^ 



iHi\il 



The indispensable 
BIRD model 43 
THRUUNE* 
Wattmeter 



Read RF Watts Directly. » 

0.45-2300 MHz, 1-10,000 watts ±5%, Low Insertion 
VSWR-1.05. 

Unequalled economy and flexibility: Buy only the 
element(s) covering your present frequency and power 
needs, add extra ranges later if your requirements 
expand. 




Dealer Programs 
NOW Available 







Frequencv Bands (MHz) 


Power 

Rang* 


2 


25- 


100- 200. 


400- 


30 


bO 


250 500 


1000 


s wails 




SA 


5(" SD 


SE 


10 wall* 


_ 


lOA 


IOC inn 


!0t 


2t wad^ 


— 


Z'j.\ 


2i(." 2iD 


2SE 


'jD walls 


■-.ill 1 


^>(l.Ji 


ilK" .IKJ 


=.UL 


UlOwatb 


T!)OH 


KIO.A 


loor looD 


UlOE 


2"iOwatti 


l-iOH 


JSflA 


2SCK. 2'50D 


2S0E 


'jWJwatis 


S(X1H 


SOOA 


SOOC SOOD 


S()OE 


i(KK)wat!s 


KKWH 


KXIOA 


lOmK KXKIO 


liK»E 


25rxi v.ans 


2iLl()H 








.SO()i) watts 


iO(X)H 









Table 1 

STANDARD 
ELEMENTS 
(CATALOG 
NUMBERS) 



MODEL 

43 

Elements (Table 1)2-30 MHz 
Elements (Table 1] 25-1000 MHz 

Carrying case for Model 43 & 6 elements 

Carrying case for 1 2 elements 

(S pecif y Ty pe N or S0239 connetptor^ ) 







\^mflR 



Novice Crystals (Specify Band Only) 



TWO WIETERS 




Motorola HT 220 Crystals 
CRYSTALS tN STOCK jn Stock 1 

Standard • Icorn • Heathkit • Ken •Clegg • Regency •Wilson • VHF 
Eng • Drake •And Others! S4.50 @ Lifetime Guarantee 



Make/Model 


Xmit Freq. 


Rec. Freq. 






• 







































THE AftfiOVED LUDIHG HAM AND CQMMESCIAL BAUJN IN THE WO^t-D TODAY. 



THE PROVEN BAIUN 




1 ^ItM^LE^ fUll- 1 nor PEP tND miH SDMI. Qrcvl-Qjrdtti 'i tc A\i M: 

J. Maps Vi\ PflOltlHl 6v ficdMsing Coa^ Liri« KactiaEion 

3. MOW ALL srwULlSS STtU HUROiUBf S0239 Eoublt Silver PIsKd 

A lU^EdVES F/B RlhTig Bi ?.i6wiTi^ Crui Li>v FictU> 

t. ElPmte CtKUR IKSUUrot v^■^;^-.^J-iJ ^if^Esr/ij fur. &.- 0,f ■ tX) u 

e BU .~:k us- NDt; AtUSlfA ^±-;t Pr^trfr ^)i!iri--^.-j:iA «i;a ^ 



,'■!« 



J'l 



: jp xcoi. i 



fTTj sr^^iEji-iJL^!rr-^i. 



RCl.-!m D^MIAH DCFCMSl DCPT. PLUS THOUSANDS Of HAMS THE 

WDRlD DVn ' 

THEY'RE BUILT TO mSl... 

BIG SIGNALS DON'T JUST HAPPEN- - 
GIVE YOUR ANTENNA A BREAK 

Linn 'A 7 niAri hT nilchri H ir 1j t\n a!AiM!t.ti :»u lint] Ic 53 
a- 71 flVi biijxtJ uti. <\ Tcdrf ™*rch[j K « IS jCa inaritrtit 
'iiia Jintj Ic 100 ir 330 cItR MvK<d sari. ~~ ■ 

AVAILABLE AT ALl LEAD>H& DEALERS. IF HOr, ORDEA OntLCr 

irii >(! Mgrai lA?;iU Baiur rtKech m^ ijffi of flJiMr 'fi^t fiai iKP' o'Jf 
OiCDuti au: Irorr sril /-rumbrr ! m ealLCi-. he wDJk o«: toT the pas'. 

Tre liiijiifilgr aF ll^i' B^lun nitli s bJilrin rijhhin^ trm'er grS ^l^E ij? 




M.. 



VIJ CU*«Af.TH 



SERIES 31 — BNC CONNBCTOBS 

Ampheiiol's BNC connectors are small, Hghtweiglit, 
weatheicproof connectors with bayonet action for 
quick disconnect applSfications. 

Shells, coupling rings and male contacts axe 



BNC BULKHEAD RECEP- 
TACLE 31-221-385 UG-109i 

Mates with any BNC plug. 
Receptacle can he mounted 
into panels up to 104" thick. 

Bl>ic <M) TO UHF (F) ADAP- 
TER 309-29a0-3a5 UG 255 

Adapts any BNC jack to any 
UHFpJug. S3. 63 
DOUBLE MATE ADAPTER 
8 3-877-385 Both coupling 
rings ai'e free turning. Con- 
nects 2 female components. 
52.72 

JACK ADPATER $1.95 
575-102-385 Adapts 
83-1SP-386 to Motorola type 
auto antenna jack or pin jack. 
PANEL RECEPTACLE 
8 3-1K-385 S0239 Mounts 
with 4 fasteners in 21/32" 
diameter hole. $1.17 
PANEL RECEPTACLE 
83-878-385 S0239SH Mounts 
in single 21/32" diameter 
hole. Knurled lock nuts pre- 
vent turning. $1.59 
BNC ANGLE ADAPTER 
31-009-385 UG-306 Adapts 
any BNC plug for right angle 
use. $4.23 

BNC TEE ADAPTER 
31-008-385 UG-274 Adapts 2 
BNC plugs to 31-003-385 or 
other female BNC type recep- 
table. $4.56 



accurately machined from brass. Springs are made of 
beryllium copper. All parts in turn are ASTR.O- 
plated© to give you connectors that can take 
constant handling, high temperatures and re.'^ist 
abrasion. 




UG-1094 

575-102-385 



BNC(F) TO UHF (M) ADAP- 
TER 31-028-385 UG-273 

Adapts any BNC plug to any 
UHF jack. $2.39 
PUSH-ON 

83-5SF-385 Features an un- 
threaded, springy shell to push 
fit on female connectors. 
$2.27 

LIGHTNING ARRESTOR 
575-105-385 EUminates static 
build-up from antenna. Pro- 
tects your valuable equipment 
against lightning damage. 
$4.80 

BNC PLUG 31-002-385 UG- 
88 Commonly used for com- 
munications antenna lead 
cables. For RG oS/U & RG 
58/U cables. SI. 59 
BNC STRAIGHT ADAPTER 
31-219-385 UG-914 1 9/32" 
long, allows length of cables to 
be joined. Mates with BNC 
plugs. $2.12 

BNC PANEL RECEPTACLE 
31-003-385 UG-290 Mounts 
with 4 fasteners in 29/64" 
diameter hole. $1.74 



PL 259 ... 90</ 
UG-175 (Adapt- 
er for RG 58TJ) 
...%U 




S0239SH 



83-5SP-385 



UG-255 






UG-88 



575-105-385 



UG-914 



AMECO 



ALL BAND PREAMPLIFIERS 




• e THRU 180 METERS 

■ TWO MODELS AVAILABLE 

• RECOMMENDED FOR 
RECEIVER USE ONLY 

• INCLUDES POWER SUPPLY 

MODEL PLF ennploys a dual 
gate FET providing noise fig- 
ures of 1.5 to 3.4 db., de- 
pending upon the band. The 
weak signal performance of 
most receivers as well as image 
and spurious rejection are 
greatly improved. Overall gain 
is in excess of 20 db. Pane! 
contains switching that trans- 
fers the antenna directly to 
the receiver or to the Preamp. 
Mode! PLF 117V AC, 60 Hz. 
Wired 8e Tested $44.00 

Model PCLP Uses 

nuvistor $44.00 



Tufts Radio Electronics • 209 Mystic Avenue • Medford MA 02155 • (617) 395-8280 



Tufts Radio Electronics • 209 Mystic Avenue • Medford (VIA 02155 • (617) 395-8280 




Now It^ Crystal Clear 



Yes, now ICOM heJps you steer clear of all the hassles of channel crystals. The new 
IC-22S is the same surprising radio </ou've coine to know and love as the 1C<22 A, 
except that [t is totally ciystal independent. Zero crystals. SoHd state engineering 
enables you to progtam 23 channels of your choice without waiTing. Now the 
ICOM performance yoii'ue demanded comes with the convenience you've wanted, 
with your ne\u IC-22S. Price: $299.00 




Hold it! 



Take hold of SSB with these 
two low cast twins, ICOM'S new portublc lC-202 and IC-502 put it within 
your reach wherever you are. You can take it with you to the hill top, the 
highways, or the beach. Three portable watts PEP on two meters or six! 

HellOf DX! The ICOM quality and excellent receiver characteristics of this 
pair make bulky converters and low band rigs unnecessary for getting 
started in SSB-VHF, You just add your linear amp, if you wish, connect to 
the antenna, and DX! With the 202 you may talk through OSCAR Vl and 
VIl! Even transceive with an "up" receiving converter! The IC-502, simi- 
larly, makes use of six meters in ways that you would have always liked but 
could never have before, in fact, there are so many things to try, it's like 
Opening a new band. 

Take hold i>f Smgie Side Band. Take hold of some excitement. Taks two. 



IC-3Q2 

^M3ier-SSB-3Watt5 f Ef ■ True (F N&iM Bianlser 
Siuilched Dia] Lights- InLemal Bafleries ■ 2CiOHH; 
VXO Tunire - l-l-l.Q, Ml.?. + 2 Morei ■ HIT! 

Pries: S2§9.m 



IC-5D2 




Mow ICOM HfYirtsdiJMS 15 Oiannels of FW to Go! 

The New IC-215: the FM Grabber 

This ^ JCOM-i /:r« fH pcrtaWE, and M ptdc aond £lni£t {in ihA ^a. 



FN cmnniu-nirrtliiir* gO rlgJit nloiia with t-xju', Lddd lasllna iiitfrnnL 

in^ki^ i(^MTi>Trj(JLHi luvBttUHal ^iii^i 41111I nnlAiuM loal -gnid rfiey 

GrabJnrDeiiblMvwdt3ilhcji[wlC.215 FM pcitni^. 



lC-245 Transceiver 

The VFO Revolution goes mobile with the unique, ICOM developed 
LSI synthesizer with 4 digit LED readout. The lC-245 o-ffers the 
most ft)r mobile on the market. The easy to use tuning knob moves 
accurately over 50 detent steps and assures excellent control as 
easily as steering the vehicle. With its optional adapter, the IC-245 
puts you into alj mode operation on T 2V DC power with a compact 
dash-mounted transceiver. In FM, the synthesizer command fre- 
quency is displayed in 5 kHz steps -from 146 to 148 MHz, and with 
the side band adapter the step rate drops to 100 Hz from 144 to 
146 MHz. For maximunn repeater flexibility, the transmit and 
receive frequencies are independently programmable on any separa- 
tion. The lC-245 even comes equipped with a multiple pin Molex 
connector for remote control. The IC-245 is a product of the 
revolution in VFO design, from its new style front panel, to its 
excellent mechanical rigidity and Large Scale Integrated Circuitry. 
Your IC-245 wiM give you the rnost for mobile. $499.00 




F»^¥4cd inlpmt 

« NpRnirBhtTO^HiF-ffMTIVillMl 

« iftdi^HlftHtotiiilDiripDhAi^ 
• C«iT«t4h rrwQnt bflhu* Bw.fltiibk 



iku\\\\i RnrElLd^ 

i llBh«<drilDl " - 




THE NEW ICOM 4 MEG, MULTI-MODE, 2 METER RADIO — IC 
211 

ICOM Introduces the "first of a great new wave of amateur radios, 
with new styling, new versatility, new integration of functions. 
You've never before laid eves on a radio Sikethe IC-211, but you'll 
recognize what you've got when you first turn the single-knob 
frequency control on this compact new model. The IC-211 is fuliy 
synthesized in 100 Hz or S kH^ steps, with dual tracking, optically 
coupled VFOs displayed by seven-segment LED readouts, providing 
any apljt. The IC-211 rolls through 4 megahertz as easily as a 
breaker through the surf. With its unique ICOM developed LSI 
synthesizer, the IC-21 1 is now the best "do everything" radio for 2 
meters, with FM. USB, LSB and CW operation. S749.00 




Tufts Radio Electronics • 209 Mystic Avenue • Medford iVIA 02155 • (617) 395-8280 



Tufts Radio Electronics • 209 Mystic Avenue • Medford WIA 02155 • (617) 395-8280 




model 333 
dummy Eoad 
wattmeter 

Fawofite Lightweight Portable-250 WATT RATING- 
Air Cooled 

Jdejl hgld se-'vicr? u^ T 'or r-!obite 2vvav rad<o— C3, n.:: ne, 

b jsinsas ben^d. 5eii 'or QRP anrsieu.' use. C3, ^vith ifo :o 

E ■.\*a"s f jll icale lo^v power range. 

■ specifications 

DC to 300 MHi 

Less than U:l w 230 MHi 

250 watti inTermitteni 

0-5, 0-&0. 0-125, 0-250 

SO 239 

A" x7" x8" 



Froquencv Rang* 
VSWB 
Power Range 
WjII meter Ranj)U 

Shipping Weight 
Prree 



2 lbs. 




_nM3del= 374 dumrrrv load wattmeter 

Top of the Line-1500WATT RATlNG-Oil Cooled 

Our highesr power c-o-y\: '"jiion unir. R.;"r:i ;o '^&00 vwaTis 
■ npui f inTerrrjriiem). Weier rang.^- are individuailv 
cs/ibrat-iii :or rugheji ^-Lutccy. 
■ (p4d1i cations 



F^rtKiiiflncv Rang* 


DC TO 300 MHa 


VSVWR 


Less than 1.3:1 to 230 MHz 


PoweF Range 


t500 watts DC intHrmittent. 




Warnirtg Ijghf signals 




maximum hitiit limit. 


Wattmeter Ranges 


0-15. 0-50. 0-300. 0- ISM 


Inpiil ConTiector 


S0^39 Iheirrtwcairy saalsd] 


Sizs 


4-3/4'- x9'- ^ 10- IM'- 


Shipping Weight 


12 lbs. 


P'ke 


S215J>0 



B^W 



BARKER & WILLIAMSON, INC. 




Economy High Power Load-1500 WATT RATrNG- 

Oil Cooled 

modeJ 384 dummv load 

Tur hrgh pnwer whifn dll yoj need is the load. 



I spec^ficaiJoRs 

Frequ^TKV Ratine 

VSiiVR 

P'Pvyer R^ange 

Conrflctor 

Shipping We igW 
Price 



DC (a 3O0 MHi 

Less tturt 1 .3: T lo 230 MHi 

1500 ^an* «(iTefmiitent. 
VUarnlrq lighT* signals 
maximuin heat limit. 

50-239 {hflim»ticallv s«jlad} 
4-3/4" )(9" KlO-1/2' 
^2 Ibi. 
£94.50 




Higfi Power-tOOO WATT RATING-Oil Cooled 
model 334A dumnnv 1<^^<^ wattmeter. 

Our most popular cornbifiatn^n unit. H^inrJIei; fuN arnsleur 

power. Ivleiei" ranges mdividuaily calibr-^lyd. Can be psnei 

mouaied. 

■ spacifications 

FisquBncy RangS 

VSWR 

Powar Ringa 



DC1O30Q MHf 
Less than 1.3:T lo Z30 MHi 
inert. 



Wal1fn8le» Ranges 

Input CanTwctar 

Siie 

Shippirtfl Wfliflhl 

Prica 



700O wdii»CW 
VJarnmg light' fignals 
maKinnum h«ai limit. 

0- fO, 0- too, 0-300. 0- 1000 
SO-239 (hermeiiciflly i^aledl 
4-3/4" x9" H 10-1/4" 
IZ lbs. 
£174-00 



LITTLE DIPPER 




nrmdel 331A 

transistor dip nieler_ ^ , 

PoriabJe RF singie ger^erator, signal n^ornior. or absorDtion 
wa*,'ene:er. Ligh:weichi {' pound, 6 oyncfis <viih all htoiIs! . 
batte'v^PQwtred unit is uieai fo"" fie'd use in lesiiriq 
iransceL-efi, turimg ar^re-^na^. eic. Cari also be u^ed to 
measure capat:ilv. i:^duci^nrt. c rcu:' Q, and ciher factors. 
JrdJspansable for e>:per -iientera. it is easi y the -rest 
vefsatile .nsirnir-em .f\ 'hp. S'^op. Cc irir.^.:ijis >v-Tsg-: trorn 
2 MK/ :o 2jO MHz in seven ranges. 

Unit constats of 5 tJ-ansistorij-ed RF dip oscillator and 
100-niicroampetfe meter circjil. Meter t:if\:uit uses a 
single-transrsior DC amplifier wJlh a potentiometer in the 
emitter circuit to control meter sensitivity A 3-posiTion 
slide switch connecis The metfir cTE^uit if> iho os^iHatOT for 
dip measut':'iTifnIs. to 3 diOde 'or absorpi'Dn ^lva^'snR;e' 
pes): Ti'?^&J'?:l'ieiilS. or pfov gc:^ 5l.li r^v.]diJi»iii,iii o\ ''-'i 
RF stgnal. 
i^reQ_=nc.v dial ^.d^ 3 c^iibf-i-i.^j tzi^re^ze [>C.'il Tor Q ana 

baniiividi^ ■tieasuieo'^eA-i. taL:ii coi has iis k>m- freaue-r^cy 
die there's no confuscn -.vC" tiuI' oe '-arfctr^s or sriafl, 
hard-lc-rsad 5cj1e5 -"^e^r tne v'eni!-";' ot :hs dijl. 



■ specit) cations 

Frequency Covflia 



2 UHi Id 231^ MH; in 7 overlapping 
ranges by plug-in cOil aiSdinblies: 
2 MHr-4ftlHi, 4 MHi- B MHz. 
fl MHr-16 MHz, 16MHi-3Z MHz. 
J2 MHl-M MHz, 50 MHi- 1 10 MHi, 
110MHi-230MHj 



Accuracy 


-.3% 


Mcdul^tion 


IOOOH1, 25STodO'>i 


Power 


9-^(oit transistor baneiy, 


V __ 


Burg*ss 2Ufi or equivaleni 


Size 


7- xZ U4" x2 1/2" 


Shipping Weight 


1 lb., 6 01. 


Price 


3120.00 



WrDE RANGE ATTENUATOR 




Model 371-1 



—■O'.ecl yOLTF 'e'Sivtif ir -.-..iT'^itrte- --om ov«:: -^inj.;. o' ijr-j 
Vi4e stci^ at-.unuaucn of l[^% ie,e: RF 5[fv>i ['c t Signal 
ci^ne^^tci'^s, pTe5ir.:^lif nrs, ;)r convene''.; Si=vien ■■■oc^er 
sw'tc^MproviCJF atienlL^aiiCi'i tron- t -cB fo 6i ^B in ' d£J 
steps Switches dre marked in dB. 1 ■2-3-5-10-20-20 Sum cf 
actuated switches (IM possnon] gives atieon^i ion With all 
s^^ Itches in OUT position, there is NO iriserhon loss 
Attenuator instoHs in coaxiyl line using UHF connectors 



■ speciflcaiiDn£ 

Pouvef Cap^Citv 
VSWR 
Impedance 
AccuiJcy 

Siz< 

Shipping Vtfdtgfil 



1/4 wall 

1 .3:1 maximum, DC to 225 MHz 

50 ohmi 

1 dB/dB, DC TO 60 MH? 

t ilB/dB '0.5 <JB. DC 10 IGO MHi 

1 dB/dS -T.0dB. DC to 225 MHz 

a-IVZ*- X 2-1/2" X 2-1/4" 

1-1/2 lbs. 



Tufts Radio Electronics • 209 Mystic Avenue • Medford MA 02155 • (617) 395-8280 




Tufts Radio Electronics • 209 Mystic Avenue • Medford (VIA 02155 • (617) 395-8280 

• Handle full 200 watts • low-low V-S.W.R. • Deliver 3 dS gain and more! •Pick the one that best fits your needs: 



rsen Kulrod 
flntennos 

MAGNETIC MOUNT 

stays put even at 
100 mph! 

MM-JM-150for144MHzuse) "^"'^ 
MW-JM-220for220MH2uss $38.50 
MM-JM-440for440MHzuse) complete 




TRUNK LID MOUNT 

No holes and low 
silhouette too! 



TLM-JM-150for144MHzuseV Only 
TLM-JM-220for220MHzuse $38.50 
TLM-JM-440for440MHz use) complete 
And 1/4 wave antenna for trunk 
and magnetic mount — $18.50 



ROOF or FENDER MOUNT 

Goes on quick and easy 
in 3/8" or 3/4" with - 
fewest parts. 
JM-150 Kfor144MHzuse 't Only 
JM-220-Kfor220MHzuse [ $31.50 
JM-440-Kfor440MHzuse ) complete| 
And 1/4 wave antenna for roof and 
fender mounts $1 1 .50 



Above antennas all complete with mounting hardware, coax, connector plug, alien wrench andcomplete instructions. 



_modo1 372 CUFREAMP _ 



COAXIAL ANTENNA CHANGEOVER RELAY 




Model 372 - $27.50 



Gei mai^imum Jegsl moadlatian vviihout dar^ger ot ^planer. 
Soird'StatG speerli preampiiiicr end Clipoe-f lor IrgnsmiHers, 
public-^ddfKss i-vsiems. and lapa recortters nastJs no 
cder^ai :.i5ivsf. 

Input IniiHdiTici IXpOQ ahrvu 

Irxiut L«VBl5 S tf:\Hinhi to 70 milUvatcs 

VoHagtGain lildB 

OuCpuI Ltrtl flS jnillintli 

OupuT lii^pM»nt< MjWOoTtrm 

Sua 2-3/4" « 3^ >. d 1/2" 




Model 377 -SI 7.95 



Ewnomicaland reliable. Can be operated from VO>t circ-uit 
far fompleisly aiiiomaiic: opefatior^ or Irom PTT or man-ual 
T/R 5\M'rh. fleteiver intujl i^ automatitativ gfOundKJ when 
thi- relay i^ in The Transmit position, Wide AC opeiaring 
voltage range and low Dper^atiftg currenl, 

i »p«tifii»tioni 
Power RsiirKi 
V5WR 

Pqwar R«luininilrf 






Stltopino Wafllit 



1000 w»n» cw izwo v.«i« sse> 

Las irian 1.1^:1. DC Id ISDMK1 
0,111s Ampare.OBta 139 vol 
UHF T^pd SO-33a 
3ira-* 1 l/T' 



flC 



UNIVERSAL HYBRIDCOUPLER II PHONE PATCH 

model 3002W acrd tnodel 3001W 




) iha lelaplione Ijnes. Five 
jive complete iieKibilLTy loc 
line and for tape recording anri 

ine or the siaiiori, TJie hybrid 



Confjeci your ji^non n 

5wiich-5eIertablE mods. ( 

palciiinci She s.M(ign to the 

ptsybacl; Ii3 Qf Irorn The 1 

circLir! prowcTH tor 53[(oril^s.i VOJ< Dperairon of ifiE phone 

patci^ A buili-in Conj/yesmp SDsecri o(ea^Qhi\sf/\\m\i&r 

( in Model 3DD?W) incteasa? the tek'el nf ^veak phone -siqrtais 

and al&a pievenXi. o^^rmoriulatiDn wtien the loqai tctEphone 

IS uied S5 [he siai^on mjtrophone. [The Comps^smfi also 

tunciioni; as a pi-eamplitiEr/h miter with the itatron 

micraphane. it desired ) 



Model 300 2W with Compreamp 
-$125.00 



Model 300 1 W without Compreamp 
- $85.00 



COAXIAL SWITCHES AND ACCESSORIES 

for antefina selectf-on and RF switching 



specilicsTions 




Line 


eOOohmi 


H«cvivtr 


4o^fw 




High ImpMlirm l50JXn oh 
«1^nBlnrdymim>c 


Tape RueordEir 


Aohnn 


Output^ to [ 


50j000«hnlf 


ft«c«iMrSPMk«r 4 ohim 


Taw Rewrdw 


0,& mBgohm 


Siie 


6^1/2" X 71/2" K 3" 


ShippiflaWl^iflhi 


3-1/2 Ibi. 


PsnM 


gr«|ur»i|«>t 




PJwnq 




BARKER & WILLIAMSON, INC. 



Model 359 - $37.50 



Dealer Programs 
NOW Available 

Increase your Trans(!in:er''E elfecin/e- ^pKf:h fjowe-r 'jO '0 
four times. Or Lise \i wUh your lape recorde-i o: puolic 
address system 1(x in^pfovad perforrnwte This two-slage, 
trans istorn;ed Audio PrearnplrlieT/Limiter c^n be gS'^d wfih . 
ail tyoes of ir-artsmfliers. Powered by a long-laiimg dry-cell 
batter/— no exrerraa! power neeicJed. InistalJs withou-t sriy 
wirirjg changes jrt your transnimer. Just mnnect she 
Ccntp/camp bestvcen youi micfOphtinE [50,D00-ohm 
dyjigmlc OJ" high-impedanM ceramitl and your transmuier^s 
mrcrDphorje inpitr ■connecioj-. Frant-panet rocr^ei' SWjICIt leis 
yOu bypasi the Ccrnpresrnp when you want lo 
Compressian leuel is-tdj^Staiile. too. 




InpEil Empedar 



etjsl 



OVIPJI L4V4I 

Ojiptn lmp«dan 



ShTpping'WaJgJil 



100 J»0 ohrm 

5 m-tiivQ'nT'to 20 rnilJivO'liii 

10 dB 

eO mittivolTs 

Du>igon2U6 or oquna^m 
2-3^4-k3"xM/2:' 

Twiliiiul sViip 



These high-quality avitches have' set the sjandard for the 
industry for years. Ceramic switches with silver-alloy con 
tBCts and alwer-plated cornlucSors give L>nJna[ched perfor- 
msoce gr^qj reliabUity '.rom 3udiO frwigencics ]Ci 150 MHj. 



eSfW coaxial switches art desig-^ed! fOr- use wflh 52- TO 75- 
Ohrti non-reacTii« ioad^, and ate power rated a[ 1000 wstis 
AM. 2000 waits &SB CannecEors are LtHF type. In^rtior^ 
loss is negligible^ ar>d VSWR is less tJian 1.2 J up so 150 



Crosstalv; (measyj-ed 51 30 WHe! is -^5 OB between edjacent 
cnjlLetsand -60 dB bei^wei alternsie ouUeis. 

ModeJs are available for de5.k, wall, or panel mouniir^g, ami 
wilti OS rti!houl protcctHve grounding of inrictive outputs. 
Radial [side- moon led) ConnecJor moclelj C3t^ &s enh^jr-wS^I 
or panel maunled, dKial (backpiale-rr^ounied) connector 
iTiQiSels yfy for p^ne-l r'nouril ing Or^ly. SS'^'S p^ifS' Sf>fce- 



Ue£ vhe seleciQr char! 
rieaj. 



below 10 choose the models you 



COAXIAL SWITCH SELECTOR CHART 







PRICE 


Outputs 


Connector 
Placement 




Mounting 




AutQjnarit 
Grounding 


Dial 
Plate 




Model 


Panel 


Wall 


Desk 


Remarks 


375 


18.95 


6 


Axial 


" 






^ 


Supplied 


PROTAK switch. GrOuJids all except selfict&d 
output circuit. 


376 


1S.95 


5 


Radial 


X 


^ 




^ 


Supplied 


PROTAX switch. Grounds all except selected 
outpui Circuit. SJxth switch position grounds 
aH outputs. 


550A 


14.00 


5 


Radial 


X 


X 






DP- 5 




6S0A-2 


12.50 


2 


Radial 


X 


X 






DP-2 




651 A 


17. SO 


2 


Radial 


X 


X 






OP-2 


Special 2-poie, 2-positJQn sv^/itc^i used lo 
switch any RF devni:^ in or out of series 
connecliOn in d tOaxial Jine See figtrre (over), 


556 


.95 


- 


_ 




X 






- 


eractet anlv. lor waH mounting ai radrai 
connector synches. 


590 


17.95 


5 


Axial 


X 








OP.5 




590G 


17.95 


5 


Axial 


X 






X 


Suppfied 


Gfou fids all e)tcept seiected ouiput circuit. 


592 


16 50 


2 


Axial 


>, 








DP-2 




59S 


1S.50 


6 


In-line 




- 


- 


- 




Grounds all ejicept sftiected output circuit. 



Model 376 

n 




Tufts Radio Electronics • 209 Mystic Avenue • Medford MA 02155 • (617) 395-8280 



Tufts Radio Electronics • 209 Mystic Avenue • Medford MA 02155 • (617) 395-8280 



Thcrt is no substitute for quality, performance, 
or tiie satisfaction of ownin.9 the wtry best. 

Hence, the incomparable Hy-Oaln 37 50 Amateur 
transceiver. The 3750 covers ali amateur bands 
1.8-30 IWz (160-10 meters). It utilizes advanced 
Phase -Lock- Loop circuitry with dual gate MOS 
FETs at all critical RF ampiifer and mixer stages. 
There's a rotating dial for easy band -scanning and an 
electronic h^equency counter with digital readout 
and a unemory display that remembers (requei^ctes at 
the nip of a switct). And that's just ihe beginning. 

Matching speaker unit (3 854 J and complete 
external VFO (3855) also available. 

See the incomparable Hy-Gain 3 7 50 at your radio 
(fcalef 01 write Department MM- There is no substitute. 



.wm. 



3354 - SS9.96 



3750 - S189S.0O 



38S5 - S49S.0O 



There is no substitute. 



vy ^^v^^ Amateur! 



Amateur Radio Systems. 



T; 



Deafer Programs 
NOW Available 



Supeic 

3-Elemeiit Thunderbird 
for 10, 15 and 20 Meters 
Model TH3Mk3 — $199.95 

Hy-Gain's Sjper 3-elemer,t 
Thunderbird delivers outstanding perform- 
ance on 10, 15 and liilO meters. The 
TH3'^k3 features separate and matched 
Hy-Q traps foreach band, and feeds with 52 
ohm coax. Hy Gain B^ta Match presents 
tapered impedance for most efficient 
3 band matching, and provides DC ground 
lo eiiminatc precipitation siasjc The 
TH3iHk3 delivers ma;(]mum F'B ratio, 
and SWR less than 1 .5:1 at TSsonamce on 
all bands. Its mechanically superior 
construction features tapei:' swaged shotted 
tubing fo; easy adjustment and larger 
diameter. Comes eqi-ipped *ith heavy 
tiitabie boom to-nnast clamp. hiy-Gain 
feiiiie balun Br^-S6 J5 recomni&nded for 
use with the TH3.^l.k3 



Electrical 


THGDJUt 


TriJMk3 


Gain — avecagK 


8.7da 


BdB 


FrDr.;-tc-back ratio 


25dB 


25dB 


SWR [at resorancei 


Less than 


Less than 


.mpedgnce 


bScr.vns 


5C ohms 


Power Fating 


Max legal 


Max legal 


Mechanical 






Longest element 


31 r 


27' 


Eccm length 


24' 


)4' 


Turning radtus 


20- 


15,7' 


Wind load at 80 MPH 


156 lbs. 


103.2 lbs. 


Maximum wind survival 


100 MPH 


100 MPH 


riet weight 


57 lbs. 


:b5 lbs. 


/Aast diameter accepted 


V/i" to 2W 


lVd"to2V; 


Surface area 


6,1 sq. ft. 


4.03 sq. 11. 



m 



HY-GAIW'S INCOMPARABLE 
HY-TOWEB 

FOR 80 THRU 10 METERS 

Model l&HT 

• Outstanding Omni-Directional Performance 

• Antomatic fea^d Sw-itching 

• Installs on 4 sq^. ft;, of real estate 

• Completely Self -Supporting 

By any standard of measurement, the Hy-Tower is unques- 
tionably the finest multi-baud vertical antenna system on ttie 
markisl today. Vii'tually indestructible, the Model 18HT 
featLires automatic band selection on 80 thru 10 meters 
through the use of a unique stub decoupline system which 
effectively isolates various sections of the antenna so that an 
electrical V* waveletieth (or odd multiple of a Vi waveleugth) 
exists on. all bands. Fed with 52 ohna coax., it takes maximum 
legal po'wer . . . delivers outstanding performance on all 
bands. With the addition of a base loadii?g coil^ it also delivers 
outstanding performance on 160 meteis. Structurally., the 
Model 18HT is built to last a lifetime. Rugged hot',dipped 
galvanized 24 ft. tower requires no guyed supports^ Top 
mast, which extend'; to a height of 50 Ft-, is 6061ST6 tapers 
aluminum. All hardware is iridite treated to MIL st>ec;s. If 
you're looking for the epitome in vertical antenna systems, 
you'll want My-Tower, Shpg. Wt., 96.7 lbs. Older No. 182, 
Price: S279.95 

NEW Special hiuged base assembly on Model 18HT allows 
complete assembly of antenna at pround level . . , permits 
eas^' raising and lowering of the antenna. 

BKOAD BAND DOUBLET BALUN 
for 10 thru 80 meters 
Model BN-86 
SI 5.95 

The model BN-S6 balun provides optimurn balance 
of power to both sides of any doublet aj^d vastly 
improves the transfer of energy from feedline to 
antenna. Power capacity is 1 K\V DC. Features 
weatherproof construction and built-in mountinE 
brackets. $15.95 Shpg. Wt, 1 lb. Order No. 242 




i. 




6-Elenient Super Thundev- 
bird DX for 10, 1 5 and 20 
Meters Model TH6 DXX 
S249.95 Separate HY-Q 
traps^ featuring laige 
diameter coils that develop 
an e xc eptionall y favorable 
L ,('C ratio and very iiigh Q. 
provide peak perforraajice 
on each band whether 
working phone or CW, 
E xclusive Hy-Gajjn beta 
match., factory pre tuned, 
insures maximum gain and 
F /B ratio witho ut com- 
promise. The THGDXX 
feeds with 52 ohm coaxial 
cable and delivers less than 
1.5:1 SWR on aU bands. 
Mechanically supeiior con- 
struction features tapei" 
swaged, slotted tubing for 
easy adjustnient and re- 
adjustment, and for larger 
diameter a.nd less wind 
loading. Fuil circumference 
compression clamps 
replace self-tapping sheet 
metal screws. Includes 
large diameter, heavy gauge 
aluminum boom. heav>' 
cast aluminum boom-to- 
mast eiamp. and heavy 
gauge machine formed ele- 
ment -t o -boom brackets. 
By -Gain's feiiite balun 
BN-86 is recommended for 
use with the TH6DXX. 



MULTI-BAND HY-Q TRAP DOUBLETS 
Hy-Q Traps 

■ install Hoi*izonta]ly or as Invented V 
■Super-Strength Aluminum Clad Wire 

■ Weatherproof Center and End Insulators 

Installed horizontally or as an inverted V. Hy-Gain doublets with 
Hy-Q traps deliver triie half wavelength peiformance on every 
dflsigti frequency. Matched traps, individually pj:etuned for each 
band feature large diameter coils that develop an exceptionally 
favorable L/C ratio and very high Q performance. Mechanically 
superior solid aluminuni trap housing provide maximum protec- 
tion and support to the"- loading coil. Fed -with 52 ohm. coas, 
Hy-Gain doublets employ super-strength aluminum clad single 
strand steel wire elements that defy deterioration from salt water 
and smoke - - - will not stretch , . . withstand hurricane-like 
winds, SWR less than 1,5:1 on aU bands. Strong, lightweight, 
weatherproof center insulators are molded froni_ high impact 
cyolac. Hardv^^are is iridate treated to MIL specs. Heavily serrated 
7-inch end insulators molded from high impact cycolac increase 
leakage path to approximately 12 inches. 

MODEL 2BDQ tor 40 and 80 meters. 100' lOV?" overall. Takes 

maximum legal power. Shpg. Wt-, 7-5 lbs S49.95 

Order No, 3S0 

MODEL 5BDQ for 10, 15, 20, 40 and 80 meters. 94' overall. 

Takes maximum power. Shpg. Wt-, 12-2 lbs, $79.95 

Order No. 383 



for Mxilti- 




CENTEH INSULATOR 
Band Doublets Model CI 

Strong lightweight, weatherproof 
Model CI is molded from high impact 
cycolac. Hardware is iridite treated to 
MIL specs. Accepts Va" or %" eoaxial- 
Shpg. Wt.. 0.6 lbs. $5.95 Order No- 
155 



MULTI-BAND ANTENNA 
Dipole Antenna — Model DIV-^0 

$13.95 

For 10 thru 80 meters — choice of one band 

A dipole antenna for the individuals who prefer the "do-it-your- 
self" flexibility of custom-designing an antenna for your specific 
needs. (Work the frequencies you v.'ish in the 10 through 80 
meters bands) . 

The DlV-80 features: Durable Copperweld wire for greater 
strength, Mosley Dipole Connector (DPC-1> for RG-8/U or 
RG-5S/U coax and all the technical information you will need to 
construct yom- custonrniesigned antenna. 



^ Jf i ? B !! »!))»])U 



END INSULATORS for Doublets Model EI 
Rugged 7-inch end insulators are molded from high impact 
cyGoiac that is heavily sejrrated to increase leakage path to 
approximately 12 inches. Available in pairs only. Shpg. Wt., 0.4 
Its. S3. 95 Order No. 156 



Tufts Radio Electronics • 209 Mystic Avenue • Medford MA 02155 • (617) 395-8280 



Tufts Radio Electronics • 209 IVIystic Avenue • Medford MA 02155 • (617) 395-8280 



WIDEBAND VERTICAL 

for 80-10 Meters 

Hy-Gain's18AVT/WB 

Take the wide band, omni -directional performance 
of Hy-Gain's famous 14AVQ/WB, add 80 meter 
capability plus extra-heavy duty construction — and 
you have the unrivailed new ISAVT/WBn In other 
wordSj you have quite an antenna. 

* Automatic switching, five band capability is ac- 
complished through the use of three beefed-up 
Hy-Q traps (featuring large diameter coils that 
develop an. exceptionally favorable L/C ratio). 

♦ Top loading coil. 

• Across- the -band performance with just one fur- 
nished setting for each band {10 through 40). 

• True 1/4 wave resonance on all bands. 

• SWR of 2:1 or less at band edges. 

* Radiation pattern has an outstandingly low 
angle whether roof top or ground mounted. 



CONSTRUCTION . , . of extra -heavy 
duty tapered swaged seamless alumi- 
num tubing with full circumference, 
corrosion resistant compression 
damps at slotted tubing joints. . .is so 
rugged and rigid that, although the 
antenna is 25' in height, it can be 
mounted without guy wires, using a 
12" double grip mast bracket, with 
recessed coax connecter. 

Order No. 386 Price: $97.00 



The Versatile Model iav <or 80 thru 10 Meters 

Tht- Model 13V LS a bw-wsE. highly efficienl vwlLcal anteiiiij ihiil i.-:iii iye 
!.jn4d t4i aiiv biind SO thru 10 reeturs .by a aimple adjnstratiiL ••l" tht 
fecJ fiojnt on the jiiatchinK bast inductor Fed with r^2 riKiii arsx. ihis JB 
n radiatf.:' ix .im.'*2i(iHiy effitK=nt (or DX ur Jivc.iL euiitua Curstmcted tif 
heavy 5;f^u^;^.' aluntinuiti tubiiin, tht^S(^dcl iH\' razy bnnntJitW Wi 3 .ihorl 
1** ii.ch niHst driven itit^j Lhf Hrwurbd it l.-; alsc; ;td:ipiabk-' Us r-ixA or Wu'*t 
moLintiii):. ihi-hly porUihkv tho Model !^V cran bcquicklv ItnrK-ked rkm-n to 

!!-i[jS Sh]j[; \Vl , .5 Ih.-, 

Order Wo. 193 Pfice- $33.00 



ALL NEW 
3- BAND, 
2 ELEMEIMT 
HY-QUAD 



■ MakcK nil Qlhi:r ijilads ubsoleic' 
»« Cnirpkit - i!otli]ns-«I^e *-'^ b;iy 

■ liiali stienglh, [ow whd li^ac! 

The HyJ^uaJ fri.T.1 Kv-Gaii. makes all oiticc rjiiads [jbstiltt=: I- 
Fiisl. if? lilt aaty quad ihal ii i:!j7iipkl<:. There is itotliing ii 

Secoiiily. 11 IS iinicjuely designed s& thai il wficomr* all uE !he pTtvioii.^ly 
iin^csirabl-e' ri:jtaie3 inli'E'C^nl in qy^di. 

TKl- dll dIuiiiLiium stFucEuce slay* jp! Tlic single Teed line ajad dinmond shape 
simplifies feerf hue touting 

l!y-Gain\ a)] rev. Hy-Quad -ijll uindfj all uljici; quad^ hu^uu^n i:\ t^EjyliierrtfJ 
!{> dt> jiwl [lial The Hy-Qnad is fiKw. ii'i Mipcriui, ii\tOinple[c ii's liio rii-sr 
quad (0 liave everytbitiEi spiciitlLTi ^fc biyKcn up Ji -iLiai^gn: elecicjcal points 
w^ilh Cycybc insulnH'TS / tri Ijand 2 elemetii coiistcucEiori with individually 
tciynaivJ c-lcirgnls with no iiilcraf [lon / Hv-Quad require!, only [mc- feed line 
fvr Ail ihrtc iuiids / individually iuT>cd j^amma inatclics on each band with 
Hj-Gsin tsClysivc vcrieM ^<^vJ 1 full wave elenieni loop* i-etjiiire no cuimg 
'itwb^. Ira pi, loading coils ■Or b^altii'C!: / heavy duly mE'-ehant'Cal consiiuetlon tit 
^ifjHi^ swijgr-d alumL/imn iubing i5]id die formsd sfircsder-io-buoni clampv I 
SKlia hea vy duty iLiiiversil booin-lo-iTiaBl s\m mp ihal i ills and [nounts on any 
masi ] Vr lo 2Vi" in JiamelLT / aluitiiniini stranded wlk. Yoj can open and 
e1{)sc Ihe band.': willi this jnlcnna Youll experience ihe thnlj of rn^al DX. 

OrderNO-244 Pnce: S2ig.95 



SPKIFtCATIONS 

Overall Itngtt^ of 5preader5 25'&" Forward g 



TurnJng radiii? 

Weight .... 

Boom aia.->ieief 
iDOfn length 
Ig^i diameiSi" 

Wiind sufi'iu^l _ 

Surface ares 

Wind load at ICO 



Input impedance . . 

VSWR .... ... . 

betteratresonaoi 

Ffonl'lo-bStK 'alio. . , , , 
depending upon e^ 
PolarjzaTion ... ... 



, ,.. 8.5 db 
131 or 

Ms^iiYium 

legal 
. . £5-35 db 
lineal height 

Horraantal 




For 1 0, 1 5, and 20 Meters 
New Hy-Gain Mode! 12 AVQ 



Completeiy self-supporting, the Model 12AVQ features Hy-Q traps... 12" double- 
grip mast bracket... taper swaged seamless aluminum construction with full cir- 
cumference compression clamps at tubing joints. It delivers outstanding low angle 
radiation. SWR is 2:1 or less on all bands. Overall height is 13' 6". Shipping weight 
7.2 lbs. Price: $47.00 Order No. 384 



New, improved successor to the world's most popular vertical! 
Hy-Gain Model 14 AVQ/WB for 40-10 Meters. 

• Wide band performance with one setting (optimum settings for top performance furrvished) 

• New Hy-Q Traps •New 12" Double-Grip Mast Bracket •Taper Swagged Seamless 
Alurriinum Construction 

The Model 14AVQ/WB, new improved succea.^or to the world famous Mndel 14 AVQ, 15 a self-supporting, 
aatoniatit: band switching vertical that delivers omnl-directionai performance on 40 through 10 meters. 
Three separate Hy-Q traps featuring large diameter coi^s that develop an except}o.nally favorable L/C 
ratio and a very high Q, provide peak performance by effectively isolating sections of the antenna so 
that a Irue 1/4 wave resonance exists on all bands. Outstandingly low angle radiation pattern makes 
DX and other long haul contacts easy, Superior mechanical features include solid aluminum housing 
for traps using air dielectric capacitor... heavy gauge taper swaged seamless aluminum radiator.. -full 
circumference compressioit clamps at tubing joints that are resistant to corrosion and wear... and a 12" 
double-grip mast bracltet that insures maximum rigidity whether roof-top or ground mounted. The 
Model 14AVQ/WB also delivers excellent performance on SO meters using ffy-Gain Model LC-SOQ 
Loading Coil. Overall height is IS feet. Shipping weight 9,2 lbs. Unsurpassed portability,,. outstand- 
ing for permanent installations. Price: $67.00 , Order No. 385 

TYPICAt 14AVQ/WB VSWR CURVES 




29 6 29,7 





^^ 








^^ 




'^ 


-~- 


■^^ 


^'■ 














14 


DO U 


10 


14 20 U 


30 




40 


14E 





_^ 






1.5 1 

3 D'1 




""" 











7 t 


40 METER 


73 


7 





ROOF MOUNTING KIT-Modei 14RMQ provides rugged support for Model 14AVQ/WB. 
Order No. 184. Price; $28.95 




Hy-Gain REEL TAPE PORTABLE DIPOLE 
for 10 thru 80 Meters Model 18TD 

The most portable high performance dipale ever... 

The Model 18TD is unquestionably the luost foolproaf high performance portable 
doublet antenna systcra over developed It has proven invaluable in providing 
reliable commanications in vital military and OQmmeroiai-applicattOhS tlirough- 
out the world. Two stainless steel tapes, ralibraced in meters, extend iVoiri either 
side of the main iiousing U(^ to a total distance of 132 feet fnr 3.5 me operation. 
25 ft. lengths of polypropylene rope attached to eacll tape ^jetmits illstellatioit 
topoks, trees, btllldinKS--- whatever is availahle far fnrming a doublet antenna s.v.'-tam. 
Integrated in the high impact housing is a frequency to iengti conversion chart 
calibrated to meter measurements on the tapes. ..makes installation foolproof. Feeds- with 
52 ohm coax. Delivers oulslandiny performance as a portable or permanent iostallatiori. 
Mea.sures 10x5';^x2 inches retracted, Wt,, 4.t lbs. 
Older No. 228 Prket S94.85 ■ - - 




!S=*-» 



tiSKiy-i^iilf^w: 




Z)s/ii5f0rL MLA-2500 $799.50 

DenTron Railio has packed all the 
features a linear amplifier should 
have into their new MLA-2500, 
Any Ham who works it can tell you 
the MLA-2500 really was built to 
make amateur radio more fun. 



' ALC circuit to prevent overloading 

' 160 thru 10 meters 

' 1000 watts DC input on CW, RTTY or 

SSTV Continuous Duty 
' Variable forced air cooling system 
' Self-contained continuous duty power supply 
• Two eiMAC 8B75 external anode ceramic/ 
metal triodes operating ffi grounded grid 
Covers MARS frequencies without modifications 
50 ohm input and output Impedance 
Built-in RF wattmeter 
li7V or 234V AC 50-60 hz 
Third order distortion down at lea"5t 30 db 
Frequency range: 

1.SMH2 (1.8-2.5) 3.5MHz (3.4-4.6) 
7MHz (6.0-9.0} 14MHz (11.0-16.0) 
211VIHZ (16.0-22.0) 281MHz (28.0-30.0) 
40 watts drive for 1 KW DC input 
Rack mounting kit available (19" rack) 
Size: 5V2" H X 14" W x 14" D Wt. 47 lbs. 



^ipo Communications 




TROUBLE FREE TOUCH-TONE ENCODER 

2,5 »H 



.POSITIVE TQUCH (KEYS DEPRESSt»M08ILE •HANDHELD 
DESK MOUNT • ND POTTED PARTS (SERVICEABLE) 
M'lL. SPEC. COMPONENTS • NO RFl • SELF CONTAINED ^ 
XTALCONTROLLED • LEVEL ADJUSTABLE FROM FRONT 



PP-1 



K Serim 15 SL-lf 701113'rie.J .viti^ n isiay lllMlJl: ll>c 


iiCotiLT, WiMiii Ki;/^ its fmssM 


wirn 1 ? sac ^«la>. hDiUiCitjfsi ConiKt: sre raitd j 


110mii(??eVi>i!S-sv..nr;iieo.BQ 


Cfltit^m; dtlsy Hi«dyi.tjri (d. tl.L- rofll, ^,,Jl^,rl^l Hcr: 


vaf, ity \iim\:wir-f_ D-5. 4:11 coljm 


Piaa Cirnr^Lmcaiio'.'^ hji ij^veliroed i nojBla fr 


1^ it^i.aLiL- ,.,^i..,rf.ei.! Tf> M l^sE 


ysarj Umi 15 cor^irjctfid wit.n ihi' ues: eompofien 




a DCSfubl!.- fTum 4 5 ■ eo Vclts ai leiDpt^riutLm fro 


r; Mla.v e [0 - l^QOF. OutQ^^t 


trir£mitt:r or ^-/M-n^. AdiMMiiWi; PulpLi Ipvel r, co 


ilrnleo wiT.n jrl iiK'.rOmerv lyDl 


mill aftesi f/om th£ troni i-- t-'.t; i:niy«-r (nyi lie^ 




nojf^ wl.L-ri iLvok-ed ^lilh S Lyit&m. 




PP-1 S3d 13 Ki^vi PP-2 SEB le 


Ktys PPrIA SW 




• ,^o,-w^, Harn 


PMK MS --"-EiM pp.2(^ ^g --'ii 


!1l.J 



B H a JH 

mmmm 

ni BUB 

B BMB 



PP-2 



IT 

1 



Tufts Radio Electronics • 209 IVIystic Avenue • Medford MA 02155 • (617) 39S-8280 



Tufts Radio Electronics • 209 Mystic Avenue • Medford IVIA 02155 • (617) 395-8280 



-C - LINE AMATEUR EQUIPMENT 





— COMMUNICATIONS RECEIVERS- 



Drake R-4C Drake T-4XC 



Solid State Li near permeability-tuned VFO with 1 
kHz dial divisions. Gear driven dual circular dials- 
High mechanical, electrical and temperature sta- 
bility. 

Cavers tiam bands with crystals furnished. 
Covers all of 80. 40. 20 and 15 meters, and 28.5- 
29.0ft1Hz of 10 meters. 

Covers 160 meters with accessory crystal. In 
addition to the ham bands, tunes any fifteen 500 
kHz ranges between 1.5 and 30 MHz, 5.0 to 6.0 
MHz not recommended. Can be used tor fi/IARS. 
WWV, CB. Marine and Shortwave broadcasts. 

Superior selectivity: 2.4 kHz 8-poie filler pro- 
vided in ssb positions. 8.0 kHz. 6 pole selectivity 
for a-m. Optional 8-pole filters of ,25. .5, 1.5 and 
6.0 kHz bandwidths available. 

Tunable notch filter attenuates carriers within 
passband. 

Smooth and precise passband tuning. 

Transceive capability, may be used to trans- 
ceive with (heT-4X, T-4X8 or T-4XC Transmitters. 
Illuminated dial shows which PTO is in use. 

Usb. Isb. a-m and cw on all bands. 

Age with fast attack and two release times for 
ssb and a-m or fast release for break-in cw. Age 
also may be switched off. 

New high efficiency accessory noise blanker 
that operates in all modes. 

Crystal lattice filter In first i-f prevents cross- 
modulation and desensitization due to strong ad- 
jacent channel signals. 

Excellent overload and intermodulation char- 
actefistics, 

25 kHz Calibrator permits working closer to 
band edges and segments. 

Scratch resistant epoxy paint finish. 
Price: $599 .DO 



Solid State Linear permeability-tuned VFO with 1 
kHz dial divisions. Gear driven dual circulardials. 
High mechanical, eSectrical and temperature 
stability. 

Covers ham bands with crystals furnished 
Covers all of SO, 40, 20 and 15 meters, and 26.6- 
29,0 MHz of 10 meters. 

Cove rs 1 60 meters with accessory crystal . Fou r 
500 kHz ranges in addition io the ham bands plus 
one fixed-frequency range can be switch- 
selected from the front panel. 

Two 8-pole crystal lattice fifSers for sideband 
selection. 

Transceives with the R-4, R-4A, R-4B, R-4C and 
SPR-4 Receivers. Switch on the T-4XC selects 
frequency control by receiver or transmitter PTO 
or independently. Illuminated dial shows which 
PTO is in use. 

Usb. Isb, a-m and cw on all bands. 

Controlled-carrier modulation for a-m is com- 
patible with ssb linear amplifiers. 

Automatic transmit-receive switching. Sepa- 
rate VOX time-delay adjustments for phone and 
cw. VOX gain is independent of microphone gain. 

Choice of VOX or PTT. VOX can be disabled by 
front panel switch. 

Adjustable pi network output 

Transmitting age prevents flat-topping. 

Meter reads relative output or plate current 
with switch on load control 

Built-in cw sidetone. 

Spotting function for easy zero-beating. 

Easily adaptable Io RTTY, either fsk or afsk. 

Compact size; rugged construction. Scratch 
resistant epoxy paint finish. 
Price; $599.00 



Power Supplies 

Power Supplies for T-4, T-4X, T-4X B or T-4XC (The AC-4 
can be housed in an MS-4 speaker cabinet). 

Model No. 1501 Drake AC^ $120.00 
Model No. 1505 Drake DC-4 $135.00 



Accessories 





Drake MS-4 

Orake MS^ Matching Speaker for use with R.4. R.4A, 
R-4B and n.4C Receivers, [Has space to house AC-3 
and AC-4 Power Supplies) 

Price: $30.00 



DRAKE MICROPHONES 

Wired for usQ with Drake transmitters arrd transceivors, for 
either push-t(>.tailt or VOX, Type of operation is determined by 
the vox controi setting at the transmitter. 

Desk Type M<xte\ No, "/075 

• Type: Heavy Duty Ceramic [>esk 
Top • Cat>le: Four Foot, 3- 
Conducwf. One Snieid,* Output 
Level: Minjs M dB (0 dB ^ 1 
vofl'mlCTotjar) • Frequency fle- 
ponte: 80-7000 Hz • Swdtcttlng; 
^^ Adapts to either push-to-taik or 

~ VOX. Price: $39.00 

Hand-Held Type Model No, 7072 

• Typo: Ceramic, hand heid • Cable: 
11- Retracted, 5' extended, PVC 3 
Cofd. t ^ieldett. Ceii Cord ■ Ca»e: 
Cycoiac * Flnlah: Grey ■ Output 
Level: Minus S5 dS (OdB = 1 volt,' 
mtcro)?ar} • Fre<]uency R«epone«: 
3I».3000 Hz • Siidlchlng: Adapts to 
either push-tD-tati< or VOX, 

Price; $19.00 





Drake SPR-4 - $629.00 

• Programmable to meet specific 
requirements: SWL, Amaleu r, 
Laboratory, Broadcast, Marine Radio, 
etc. 

• Direct frequency dialing: 150-500 kHz 
plus any 23 500 kHz ranges, 0.5 to 30 
MHz 

• FET circuitry, ali solid state 

• Linear dial, 1 kHz readout 

• Band- widths for cw, ssb, a-m with 
built-in LC filter 

• Crystais.supplled for LW, seven SW, 
and bcbartds 

• Notch filter 

• Built-in speaker 




-Drake DSR-2 - $2950.00 

• Contiriuous Coverage 
10 kHz to 30 MHz 

• Digital Synthesizer - - 
Frequency Control 

~ '• Frequency Displayed 
to 100 Hz 

• All Solid State 

• A-m, Ssb, Cw, RTTY, Isb 

• Series Balanced Gate 
Noise Blanker 

• Front End Protection 

• Optional Features Available 
on Special Order 




Drake FS-4 
Digital Synthesizer 



$250.00 



The new solid state Drake FS-4 Synthesizer opens the 
door to a new world of continuous-tuning shiDrt wave! 
Combines synthesiied general coverage flexibility with 
the selectivity, stabilMy. frequency readout and reliabi I- 
liy ot the Drake R-4C or SPR-4 Receivers. 

♦ Intef^aces with aL R-4 series receivers artd T-4X series tfans- 
mitlQfs: (H-4, R-4A. R-4B. R-4C. SPR-4. T-4. T-4X. T-4XB and 
T-4XC). without moditicalioFi. • MHy range is set on FS-4, w/lh 
kHz readout raken from recsivar dial. • ComplDte geTieral 
coverage — no fango crystals 10 buy. *T-4/T-4X series transmit- 
ters transceive on any FS-4 traquency. whan used with R-4 
series receivers. • Readout 1 kHz with Drake PTO. 
Price: $250.00 



Tufts Radio Electronics • 209 Mystic Avenue • Medford MA 02155 • (617) 395-8280 



4 



Tufts Radio Electronics • 209 Mystic Avenue • Medford MA 02155 • (617) 395-8280 



6 METER BEAMS 




3-5-6-10 ELEMENTS 

Pnivfn pcrl'firjliiintii! h-iini vugged, full kl:4C, 1 .mCtey iieainS. 
E]<?jnc!U .-i|inqiiie.saiid tcnstiiJ^ Imve bcon ciii-efiiLl.v ti^KitiPerix] to 

jTivf bi^r^i fiiiUcni, hiffh tnuward ^a.in, jjoftd iiOTil t» bur^- mtio 

Eccr:i& ;irc ri'-'i;^ vl .iiuL elc::!ients art- ^''■i ' - '^/H" .<Ky -Aall 

Ji'iste.-i hiin: I J-'H' - I I ''■i"b»fwiis. Th"? Catvi" ll^i-iKm^nt bca!«5 
hsvc I E-^" - i t/2" 'jiG'tSi.i. Al! bradei-Es ,^7^ heiiy e:auge 
!:irmcrt aidm-r.u".r.. BriRJii Hnishcac- plEisflLi't^!Lt>ftrt-jw.tjLi£iabl>€ 
t&r uf) \f. I -'. -M ■ inasf Gn i ai*J s »?Jqmc/ii a;:il ^ tm v LaJ l^i 
elt-TTicr.; liuaiTiM- A-1 ntc^^iLs .-r^y !>b njo^niee: ;:5r b£iri'-On(ai tir 
ver!'i-al pfi|Birir.s!:ie«. 

?ila-,rh anil Ij^Ml- n <"Cf5^ filling for i;(ro*1 'iS t.i>rm ftcd. 'J'jie.^^c 
■,;i_: %ins :!rf fa.Mri' r.ir^rktd niyi £(r;,pj;e:f u-jlh ir.^i: i-ri-'.iriiis for. 



□tna?i!:l"7Ti 


! ! 


-.-,.■- -■— 


f^-l'.Tcr.i 


;c .. , .*-.: 


5a.«l!»] r,T. 


z-.^: . 


A^c; 


A5t)t? 


Ai'_ ::. 


Bn.-j-. ^.'lU 


u' 


-.3 


2n' 


2^ 


LoriJili: l-i. 


■ :7 


n?' 


11? 


11?- 


Turn i;..ii ,■ 


6' 


?■ iV 


IT 


13 


Fivri Gmn 


7idB 


5.:«y 


11 :j JS 


13d& 


F.'B H..[ifi 


20 JB 


?4dE 


2C- irB 


?Bria 


W'lirjM 


7 ll>;, 


11 I'bs 


1 a H>i 


25lbi 




RINGO 
RANGER 



4.5 dB' - 6 dB" 
Omnidirectional 

GAIN 

BASE STATION 

ANTENNAS 

FOR 

MAXIMUM 

PERFOftMANCE 

AND 

VALUE 



Cush Cr;tft has created another firit by making the 
v^'^orld's nio.^t popular 2 meter antenna twice ;ls good. 
TItc n^w Hin^o Ranger i^ developed fitim the haaic 
AR-2 .vitii three h&!f wave;; in phase and a one clg-hth 
Mive nKiti'hiiJK stub. Ki?igo Ranger «"ive.s an extremely 
:o\v nr.pie oi r:i(\\r^t''ar. for better signal crjvei-nRe.. it is 
tun:iVjie over 2. :>r&iid ireqiseney rangv ariLi pei-fecHy 
malrheri to ^I'l ohm coi:x. 

ARX-2. 137-160 MHz. d lbs., 112" 
AHX-220. 220-225 MHz, 3 lbs.. rS"^ 
ARX-450, 435-450 MHz. 3 lb£.. 39'^ 

■' R-c'tftJiC* -i wa-.V! whip usts: as ^.^1.-1 E!:ir^dird by many 

Work fiLl! .j-^Metirig into more reaeaTers H^ii e^:te!ti1 the 
radios (-( v'»ih direct cor.tACts with the new Eingo 
Ran per. 

Y;nj cnn itp date your present AR-2 Rinco \Tith the 
^i]JT^p[e lifirtlljon of this e^tende. kit. The kit iiuludeu 
the pJKi.'^iijy: tJetw'OVk and necessary element extension.":. 
Tin? only modifications required a,Te easy to make saw 
slits in tlie to]: section of your antenna. 

AR)(-2K CONVERSION KIT 



2 METER 

ANTENNAS 



FM 






MwJi;: ULWnbrr 


An-2 


An-25 


AT.-e 


AR-SrD 


.^F.^w 


Prciiucrnv ?tHK 


rS5-17S 


iaD-175 


50-:-! 


:?ci-2Zi 


1-19.160 


Pomor— Hdlj: W^M^ 


]00 


SQO 


lOG 


mo 


2'j.r.' 


Wind :iTPi *;i ft 


2r 


21- 


57' 


50' 


.;o- 



B-l POLE "-^J ii^ 'I tl^ O^iii over ;i 'i ^/a.^■e dipok' Ov^niJl tmUiirtfL JtiigU: 
147 HHi SE' W.fl MHi - IS". 136 MHi. S\ p&^Icitl 3W ft dB j^tn, 

JSe ■ "D tin rr.ilr, .'■? olim feed Inhes PL 2rt9 cptsnectoi'. Fucimpo inrtunae^ i 
complete dLpcili iiii-itriibliei. uii nsouiitiaK btniBns. hAmiBs arnl nil futrftware. 
Verlicrvl Sijppwt ni:"ii.t rwi: Mipplied. 

AFM-IO m - 1^ MHb, IflfK) ■K.-ti5. w:nd .-ireu ST* ■!-] ft. 

AFM-MD 1i31 - liO .MHi, KWt) watLs. winiL firta 1 ^3 kij. ft. 

D-PCWER ^JICK 'f'lP 5'K MFfift' (22 rfetTttf.t ami/i f-jr 2 lustiK- &"M. ii^er 
Iv-o Alt"- II yit-.K v/llh iL Kori::QnT.a! luountitif 'MhiiTL ^CB^tlal h.irn*'!'^ [inil 
?J! h.trd-tn:-*. Far.-.-ani Ksir. 16 dE, FB -a:t3 ?i iJB ', )w.*r b*/i(r.-.n1t:; 
12 <i:incp.:;«iii 1 ji" s !^" '•( iCi' . iu.-r. raitis ^0 ' A-t-h.: it. d-; . ij ^nt.: £ted 



AlH^ 



d-vag: s: 

pv?r Hip 5 



.:;K'4G ►■TS VPK iK,.-t.jAs*.birk.-i3uou.; rwoT":!! tail.-: JtiiT 
.IHATK ii'BtjeCetK i etsoKBt st*tts»t" Mil 



Al*:-:^ 



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:imr.irsiti5IUl Titf^- f JI iw FM icA v^ttK^l p^aximxhc.*i. TSf Sun: and m.n eie 
ir.efil mffUtb. raa be tr«r^7- i^e Rvcustei, All aT^ mt+d tii lLj*0 ■na'ti 

Mo[3cl XuTr.lwr AUT-ll A-l*7-l A113-]l AH-O 6 

BoowLucCwV elr m ' -llr W.^^O" 5i)'.l3' SJ' . M" JC,"'. 2S" 

\V.t;hl.:Tl:ni rirtlJh fi Ic . T2' 3 Is.'i., 44" 4 Itlb . C(J' n Ih^ . !>; ' S Init. &I' 

Giin.'FvB faticrdB l^S/Sfi &;2S ^S.i 23 ]3 -JJ lS.?/Jfi 

V; Powei- boajn ■iS" flS' 4S= 50" Jft' 

Winrj nco:i sii. n 1,21 .43 .3a .SO SO 

F-t-eauciicy MH:^ M^-14a L46-14a 440-^M ■l'iO--l50 220-225 



F-FM TW/IST i^ -1 tlB ■fii.ijn: Ten ■cl.oincn.ta horiiDntiil pul^i-iaalLij:i (■or low 
eati coveniH'' ;i:iil U-[i clciiiciitii vi^rLiLa.! poiariz:ition ffir FM covcrsi-se. For- 
w^inJ K^un 13 1 [[B. K li tjilh) :i2 dH, biMjrn lenjjth 13.0 \ weL^iht 10 L&t, longest 
Flemen*. 10' , :;::,' olirii KtdJi MaLih dnvan elements tik* PL-^JSfi i:tfffnt£iors. 
ijKPE t-Ac ;,cp;l;-.l:u' E-i'Sil iJnp---. 



/y/6// PERFORMANCE 
VHP YAGIS 




3/4 , 1-1/4, 2 METER SEAMS 

The swnd^iri.! of Cumparisonin amateur VH7.''t'HF' (onimuniL-J- 
tiona Cush ClmIL yj;;is oomhine ,il] out perrorm:inL-c iini: reliii- 
bilily \v\lh opi-LiiiLini si/L- for ease ni agsEniblv ;ind moiintinf; :it 
your ^Ue. 

Lighlwifiqhl ycl ri:t.-:;r-d. the ^'j-.enrvr^s >..ivc L- -L'j ' t'- Ii- tc! id 
aiamLn_:n ^Icinenlj^ with S-'li ' L'C::^e^5e^^'.;.J^l5 mr^„r:;L-rl *iii !if :!i'v 
QUiy fornlfcl bc.lCkCIs- a.-wms are i * and T/a-' ri.t!. aljnijr.::rr. 
tubing. ^!asL rmjunts jf 1 ■" ro-rmec ilmmnium hivc arJjustaLlc- 
u-bolis for -p I'i >!'':£■ i3. D. m^5':s. Thpy cyn iw r:.v-^ic4 
for hsrircinLjl t-r vtrtk':t^ puliirJKaitR--!. Complete :nslrut.-liui:= 

^.ie-\ fca!-.ir.- LnL?Ei.::!- n kjio^i^atl p.eddi Mslch fi.r j;rt /t fi:: nhm 
COa>;i2l rO'jd v.ilh n ?,Viinl2.rC PL-251j iltUn^. ATi rltnli;nta are 
spact'<^ at ,2 n.,.vt-U-ii£T:: ^.-.it tapered for .ni\.ri ■.'•.: ^v.i- .I.MdLh. 



MOtKl ^-.1 


AU-l 7 


AIJVA. ■! 


A7?lj 1 1 


A^3G 11 


DcSCf:,-'':i3r- 


:?tn 


2^ 




^■.m 


Elemenij 


7 


11 


11 


11 


Boom Lnqfh 


9S- 


144- 


;0E" 


5? 


Wef^lM 


■1 


G 


4 


3 


Fwd. Gsin 


11 JE 


13 dB 


13dB 


13 OS 


F.'B RjTio 


?6dB 


?Sd3 


2Sde 


7hA& 


Fwd. Lobs Ci* 










V^pwr. til. 


46 


42 


J2 


r]2 


SWHIy^FrcL). 


l.to 1 


1 to 1 


t ta 1 


1 m 1 




VHF/UHF BEAMS 

A50-3 $ 32.95 
A50-5 49.95 

A50-6 69.95 

ABO- 10 99.95 

AMATEUR FM ANT 
A147-4 $ 19.95 
Al 47-11 29.95 
A147-20T 34.95 



A 147-22 

A220-7 

A220-1 1 

A449-6 

A449-1 1 

AFM^D 

AFM-24D 



84.95 
21,95 
27.95 
21.95 
27.95 
59.95 
57.95 



A144-7 
A 144-11 
A430-1 1 

EMMAS 

AFM-44D 

AR-2 

AR-6 

AR-25 

AR-220 

AR-450 

ARX-2 

ARX-2K 

ARX-220 

ARX^50 



21.95 
32.35 
24.95 



54.95 
21.95 
32.95 
29.95 
21,95 
21,95 
32.95 
13.95 
32.95 
32.95 



D;(K -..10 53.95 



CX-220 JT.K 






1-1 S2-ohm bi-lun 
Ven, Pol, B^ackoi 
i?0 El.) 



995 DX'VPe 9.9G 



Tufts Radio Electronics • 209 Mystic Avenue • Medford MA 02155 • (617) 395-8280 



Tufts Radio Electronics • 209 Mystic Avenue • Rrtedford MA 02155 • (617) 395-8280 



why waste watts? 

(SWR-IA $25.95) 




SWR-1 guards against power loss 

If you're not pumping out all the 
power you're paying for, our little 
SWR-1 combination power meter 
and SWR bridge will tell you so. You 
read forward and reflected power 
simultaneously, up to 1000 watts RF 
and 1:1 to infinitv VSWRat 3.5 to 150 
MHz. 

Got it all tuned up? Keep it that 
way with SWR-1. You can leave it 
right in your antenna circuit. 




ELECTRONICS 



.1- 



I 



DELUXE 

7-13 TRI BAND 

MOBILE 

ANTENNA 

• AutomatiuOy adjusiv in 
])ropcr ri^saj'L:n».-e inr 20. 4(i 
anci 75 inctcr^ 

• J'nwer isicii III 500 \\'.ii"i 
P.K.P. 

• Includes haue section, duio- 
in^licoil and whip Lop sec- 
tion, 742 Anlenna 

Price; $109,95 



If 



EXCLUSIVE 
DELLXE 
S-BAND MOBILE 
4S .4NTENNA 

• .'\li b^rtJ inanual s-.vi*Lhing 
anlecina tor 10. 15, iO. 40 
and 75 nicttTM 

• Power raltd at 1000 Walls 
P.K.P. 

• Iiidudcs W,i^ set'liun vJilh 
mobjiecoil and six fnol w}iip 
lop se;;TiorL 45 AnltTin-^ 
Price: $119.95 



SWAN METERS HELP YOU 
GET IT ALLTOGETHER 



These wattmeters tell you wMat's going on. 

With one of these in I ine wactmeteR power readi ngs' For wt^atever ourpose 



you'll know if vouTe getting it all 
toget her ail the time Need high ac- 
coracv? High power handling? Peak 



weve got the wanmeterfor vou. Use 
vour Swan credit card. Applications 
at voor dealer or write to us. 







JMR /MOBIL-MR" 

Two-way-radio headset with superior (idelity 

Eleclret-Capacitor boom microphone and 

palm-held talk switch. 



$69.95 



Wt*i6tia in.iiitt w*n- 

■nnerWitii Mitstie-. Scdtei 
TC Mao vuttf Hcw iia> 
fMOOfli* oirKticoait&jp- 
hT for Tntolniim^cnir^^' 



WHJ4«0 FcH-r«aiainii 
Witnrrtaf. suat bus 

wPHP. ni«ji with int n«» 
of a iwit£n true pc2t 
Doww of wmr ilngie- 

Wisr iTCOn:!. on 5SH 



WIWiHOIKgh'Anuracv In- 
Un» WBtrmnef. -Jft*. il'i 
so* Jfcor^co on 5. 'Ji. 
too Jiid iscc nasf Scam. 
3 to M Whz- Fcr*3nj ana 
tft\ieirti irtiiW USE K 
izf Tr?uBle-£r(30iirr9 tea. 
S74.M 






SWAN LINEAR AMPLIFIERS A Mark [I 2000 
watt P.E.F. full legal input power unit ox the 
1200X niatchm^ Cygnet 1200 watt P.E.P. input 
powerhouse with built-in powet supply. The choice 
is youis. $849.95 



NEW Swan MMBX 

Mobile Iznpcdaiice Matcher 

It keaps your transmitter and your 

speaking terms for a song. Price: $^3.9 

CYGNET 1200X PORTABLE 
LINEAR AMPLIFIER 
To quadruple the ovitput of the 300B Cygnet de 
novo, simply add this matching unit for more than 
a kiiovcatt of power. Complete with self-contained 
power supply and provision for external ALC, this 
C.vgnet offers t-xceplionally hi|^h efficiencv and 
linearity. S349.95 

Additional Swan products include: fixed and mobile antennas, VFO's telephone patch, 
VOX, wattmeter, microphones and mounting hitfi. As another extra service, only Sivan 
Electronics offer.'? factory-backed financing to the amateur radio cotmnunity. Visit an 
authorized Swan Electronics dealer for complete details js^ ^^mm^ ^^ 

^^ ELECTRONICS 





/MODEL 

1015-/4 



FOR BROADCAST-QUALITY TRANS- 
MISSION AND RECEPTION FOR BOTH 
MOBILE UNITS AND BASE STATIONS. 

• Boom-mounted electret-capacitor micro- 
j>hone delivers studio-quality, undistorted 
voice reproduction. Variable gain control 
lets you adjust for optimum modulation- 

• Cushioned earcup lets you monitor in 
privacy -■ no speaker b-lare to disturb 
others. Block.'? out enviroiimenLal noises^ 
loo. Made of unbreakable ABS plastic. 

• Headband splf -adjusts for comfortable 
wear over long hours. Spring-flex hinge 
lets you slip headset on and off T.\nth 
Jtist one hand. Reversible for right or left 
ear. 

• Headset can be hung on standard micro- 
phone clip. 

•Compact palm-held talk switch lets you 
keep botii hands on the wheel for safer 
-driving. Msdp of unbreakable ABS plastic. 

•Buittin FET transistor amplifiei" adap'^ 
microphone output. t,a any transceiver 
inipedance. 

■ Compatible with most t-wo-way radios in- 
cluding 40-channel CB units. 

•Built-m Velcro pad for easy moiinting of 
the talk switch. 

• Made in U.S.A. 

SPECIFICATIONS 

Earphone impedance 

and type: 8 ohms, dynamic 
Microphone type: Electret capacitor 
Microphone frequency 

response: 200-6000 Hi 

Amplifier type: FET transistor, 
variable gain 

Amplifier battery 7 -volt Mallory 
power: TR-175 
Switching: Relay or electronic 

IDEAL FOR EVERY TWO-WAY RADIO 
COMMUNICATIONS NEED . . . 
CB operators - Amateur radio operators ■ 
Police and lire vehicles • Annbulances and 
emergency Vehicles • Taxis and truckers • 
Marine pleasure and work boats - Con- 
struction and demolition crew5 • Industri- 
al communications • Security patrols * 
Airport tower and ground crews • Re- 
mote broadcast and TV-camera crews • 
Foresters and fire-watch units • 



Tufts Radio Electronics • 209 Mystic Avenue • Medford MA 02155 • (617) 395-8280 



Tufts Radio Electronics •209 Mystic Avenue • Medford MA 02155 • (617) 395-8280 



A new precision clock which tells time anywhere in the world at a 
glance, has been announced by Yaesu Electronics Corporation. The time in 
any principal city or time zone can be simultaneously coordinated with 
local time on a 24 hour basis. After the initial setting, as the clock runs, a 
Time Zone Hour Disc advances automatically, showing correct time all 
over the • world without further adjustment. The clock is especially 
designed to withstand shock and may be hung on a wall or placed on its 
desk mount. The clock wUl run an entire year on a single 1.5 volt flashUght 
battery and the mechanism starts as soon as the battery is inserted. It 
measures six inches in diameter by two and one half inches deep. An 
excellent item for the business office, ham radio operator, short wave 
hstener, boat owner, and others who want an accurate dependable clock. 
Price: $30.00 Amateur net. 



NYE VIKING 

CODE PRACTICE SET 





No. 114-404-002 
Get the RIGHT START! 

With a NYE VIKING Code Practice Set vou get a sure, smooth, Speed-X model 
310-001 transmittrng key, a linear circuit oscillator and amplifier, with a built^n 2" 
speaker, ali mounted on a Ineavy duty aluminum base with non-skid feet. Operates on 
standard 9 V transistor type battery (not included). Units can be connected in parallel 
so that two or more operators can practice seriding and receiving to each other. List 
price, $18.50. 



Fully Aih Tested - Thoyssnds Alr&aCfy in Use 
#ie 4<]% Copper Waid wire aniMalwl to it ^andlos Ii4{« soft Cooper wim - 
Rated for btrttor than full lesal power AM/CUV or SS&Coaxial or Balanoad 
50 to 75 ohm feedlTne ~ VSWR under t.S to 1 et moat h»i^ts - StainiBB 
Steel henJware — Drop Proof Insuletorf — Terrif Jo Performance — No coih 
0^ tt^lK ti> brnak doiwA or chango under Meathtr BOhdrtions — CompMeFy 
A«$en^b|ed ,^dy to put up - Guaj^tttMd 1 year - ONE DESIGN DOES 
IT ALL. 



Manufactured Si Guaranteed by 

MOR-GAIN 

2200T South 4th Street 

Leavenworth, Kansas 6604S 

(913) 682-3142 



MODEL 

4O20 HD 
40-10 HD 
80-40 HD 
75^40 HD 
75-40 HD (SPl 
75-20 HD 
75-20 HD (SPl 
75-10 HD 
75-10 HD (SPl 
S0-10HD 



BANDS 

(MEtersl 
40/20 

40/20/15/10 
30/40 + 1 5 
75/40 
75/40 
75/40/20 
75/(50/20 
75/40/20/T5/10 
75/40/20/16/10 
30/40/20/15/10 



PRICE 

S49.60 
59.50 
57.50 
5500 
57.50 
6S,50 
56.50 
74.50 
74.50 
76.50 



WEIGHT 

(O2/K9I 

36/. 73 

36/1.01 

41/1.15 

40/1.12 

40/1.12 

44/1,23 

44/1.23 

43/1,34 

4B/1.34 

50/1,40 



LENGTH 
IFt/Mtri) 
36/10,9 
38/10.9 
59/21.0 
66/20,1 
65/20.1 
66/20.1 
66/20.1 
65/20. 1 
66/20. 1 
69/21 



NO TRAPS- NO COILS- NO STUBS- NO CAPACITORS 

MOR-GAIN HD DIPOLES . . . •One Eialf the Sength of conventional 
half-wave r^ipoles. • Multi-band, lylulti-frequency. • [Vlaximunrt effi- 
ciency — no traps, loading coils, or stubs. • Fully assembled and 
pre-tuned — no measuring, no cutting. •AH weather rated — \ KW AM, 
2.5 KW CW or PEP SSB. •Proven performance - more than 15,000 
have been delivered. • Permit use of the full capabilities of today's 
5-band xrjvrs. • One teedllne for operation on all bands. • Lowest 
cost/benefit antenna on the market today. • Fast QSY — no feedline 
switching. ♦ Highest performance for the Novice as well as the 
Extra-Class Op. 

EXCLUSIVE 66 FOOT, 75 THRU 10 METER DIPOLES 

NOTES 

fl All models above are furnished with crimp /solder lugs. 

■ All models can be furnished with a SO-239 f einale coaxial connector 
at additional cost. The SO-239 mates wiUi the standard PL-259 male 
coaxial cable connector. To order this factory installed option, add the 
letter 'A' after the model number. Example: 40-20 HD/A. 

■ 75 meter models are factory tuned to resonate at 3&S0 kHz. (SP) 
models are factory tuned to resonate at 3800 kHz. SO meter models are 
factory tuned to resonate at 3650 kHz. See VSWR curves for other 
resonance data. 





SAVE YOUR RADIO! 




DESIGNED FOR COMMERCIAL USE UP TO 1000 MHZ. 

The TUFTS SAVE-YOUR-RADIO bracket can save you a 
bundle , . . and a lot of hassle. Why worry about rig ripoff 7 The 
TUFTS SYR bracket" mounts quickly'cind easily in your car and 
makes it possible to snap your rig out of its bracket when you park 
and put it out of sight. 

The connector system has a special coaxial cable connector 
which will provide you with a lossless connection right up to 1000 
MHz! No loss! In addition to the ^quick coax connector there are 
also four power and accessory connections which are made 
automatically when the rig is slid into its bracket . . . just what you 
need for feeding power and loudspeaker connections to the set. 

This is a rugged bracket and connector system . . . it'll take a 
beating. There is a hole on each side of the 1 6 gauge steel plate for a 
padlock in case you want to leave the rig for short periods in its 
bracket. They'll have to rip out the dash to get if". . . and it won't be 
the first time for that. 

With two of these brackets you can bring the mobile rig into 
the house and use it in seconds. On trips you can takean AC supply 
for the rig and use it in your hotel room. Price: $29.95 



3g*t 





No, 114.320«I3 -$SjSO 

No. 114.3Z2403 -BraH-SIO 

NYE viking speed -X KEYS 

NYE VIKING Standard Speed-X keys feature smooth, adjustabJe 

bearings, heavy-duty silver contacts, and are mounted on a heavy 

oval die cast base with black wrinkle finish. Available witb 

standard, or Navy knob, with, or without switch, and with nickel 

or brass plated key arm and hardware. 

Pamper yourself with a Gold-Plated NYE VIKING KEY! 

Mod.el No. 114-31C-004GP has all the smooth action features of 

NYE Speed-X keys in a special "presentation" model. AU 

hardware is heavily gold plated and it is mounted on onyx-Hke jet 

black plastic sub-base. List price is $50.00. 



CODE PRACTICE SET 



NYE VIKING SQUEEZE KEY 

Extra-long, finger-fitting molded paddles with 

adjustable spring tension, adjustable contact 

spacing. Knife-eflge bearings and extra large, 

gold plated silver contacts! Nickel plated brEiSS 

hardware and heavy, die cast base with 

non-skid feet. Base and dust cover black 

crackle finished. SSK-1 — S23.45. 

SSK-ICP has heavily chrome-plated base and 

dust cover. List piice, $29.95. 

You get a sure, smooth, Speed-X model 



310-001 transmitting key, linear circuit oscillator and amplifier, virith a 
built-in 2" speaker, all mounted on a heavy duty aluminum base with 
non-skid feet. Operates on standard 9V transistor type battery (not 
included). List price, $18.60. 

PHONE PATCH Model No. 2B0-46-1 measures 6-1/2" wide, 2-1/4" 
high and 2-7/8" deep. List price, $36.50. Model 250-46-3, designed for 
use with transceivers having a built-in speaker, has its own built-in 2" x 
6" 2 watt speaker. Measures 6-1/2" wide, 2-1 /4" high and 2-7/8" deep. 
List price, $44.50. 



Tufts Radio Electronics • 209 iVlystic Avenue • Medford MA 02155 • (617) 395-8280 



Tufts Radio Electronics • 209 Mystic Avenue • Medford MA 02155 • (617) 395-8280 




• Model TA-33 

• 3 Elements 

• lO-l db Forward Gain (over isotropic 
source) 

•20 db Front-to-Back Ratio 
The Mosiey TA-33, 3-element beam provides 
outstanding 10, 15 and 20 meter perfor- 
mance. Exceptionally broadband — gives 
excellent results over full Ham bandwidth. 
Incorporating Mosley Famous Trap-Master 
traps. Power Rating — 2KW P.EJ>. SSB. The 
TA-33 may also be used on 40 meters with 
TA'40KR conversion. Complete with hard- 
ware. $306.50 

MULTI-BAND BEAMS 

TRAP MASTER 33 ... 10, 15 & 20 Meters 

• Model TA-33J1:. 

• 3 Elements 

• 10.1 db Forward Gain (over isotropic 
source) 

• 20 db Front-to-Back Ratio 

The TA-33Jr . . . incorporates Mosley Trap- 
Master Junior traps. This is the low power 
brother of the TA-33. Power Rating — 1 K.W 
P.E.P. SSB.. $151.85 




TA-33JR. POWER CONVERSION KIT 
MODEL MPK-3 

Owners at the Mosley Trap-Master TA-33Jr. 
may obtain higher power without buying an 
entirely new antenna. The addition of the 
MPK-3 (power conversion kit) converts the 
TA-33Jr, into essentially a new antenna with 
750 watts j^M/CW and 2000 watts P.E.P. 
SSB. S52,25 




TRAP MASTER 36 . . . 10, 15 & 20 Meters 

• Model TA-36 

• 6 Elements 

• Forward Gain (over isotropic source) - 10.1 
dh on 15 & 20 meters, 11.1 db on 10 

meters. 
Front-to-Back Ratio on lU bands. 20 db. 

This wide-spaced, six element configuration 
employs 4 operating elements on 10 meters, 3 
operating elements on 15 meters, and 3 
operating elements on 20 meters. Automatic 
bandswitching is accomplished tlirough 
Mosley exclusively designed high impedance 
parallel resonant ''Trap Circuit." The TA-36 is 
designed for 1000 watts AM/CW or 2000 
watts P.E.P. SSB. Traps are weather and dirt 
proof, offering frequency stability under al! 
weather conditions. S335.25 




MOSLEY AK-60 MAST PLATE ADAPTER 

Mast Plate Adapter for adapting your Mosley 
IVi" mounted beam to fit 2" OD mast. 
Complete with angle and hardware. $11.15 



^@BH^ 


mi -r'i 


F^i^i*a^^i2 




o .o, n^_n-?'^=8'- 


JSfiB 



A brilliant new 2 meter transceiver 
with every in-demand operating 
feature and convenience 
KLM MULTI-2700 - $695.95 

^Synthesiser and VFO. 

*All modes; NBFM, WBFM, AM, 

SSB W//USB/LSB and CW. 

• Frequency synthesiser (PLL) 

3 Knob. 600 channels. 1 kHz steps. 

• VXO, plus or minus 7 kHz. 

* LED reado^it on synthesizer. 

• Standard 600 kHz splits plus . . . 

• Two "oddball" splits. 

* OSCAR transceive 2 to 1 meter operation. 

•OSCAB receiver built-in. 

• Connectors on rear for separate 2 



meter and 10 meter anrennas, 

• Built-in VFO (continuous coverage, 
144-143 MHz in 1.3 MHz segments. 1 
kHz readout). 

•S pole SSB filter plus tivo FM 
filters. 

• lOO kHz crystal calibrator, 
•voice operated relay (VOX) or 
p-t-t. 

*Audio speech compression. 

• Noise blanker. 

• R IT, plus or minus 5 kHz. 

• Power out/"S" meter, 

• F M center deviation meter. 

• low minimum output power. NO 
TUNING! 

• Hi-Lo power provision. 

• Suilt-in AC/DC power supply. 

• Double conversion receiver. 16.9 
MHz and 455 kHz 1-Fs. 

• Receiver sensitivity: 

FM: 0.5/JV for 28 dS S/N. 

SSB/CW: 0,25JLW for 14 dB S/N. 

AM; 2;JV for 1 dB S/N. 
•Size; Inches: 5H, 14.8SW, 12D. 
MM: 128H, STSW, 305D. 

• weight; 28 lbs. (13 KG). 




Dealer Programs 
NO l/V Available 




CLASSlC-33 ... 10. 15 & 20 Meters 
Model CL-33 

• 3 Elements 

• lO.l db Forward Gain (over isotropic' 
source) on all bands. 

• 20 db Front-to-EacIs Ratio on 15 & 20 
meters, 15 db on 10 meters, 

BRIDGING THE GAP . . . The Classic 33, 
combines the best of two Mosley systems. 
Incorporating Mosley Classic Feed System for 
a "Balanced Capacitive Matching" system 
with a feed point impedance of 52 ohms at 
resonance, and the Famous Mosley Trap- 
Master Traps for "weather-proof" traps with 
resonant frequency stability. This extra 
sturdy multi-band beam. Model CL-33, for 
operation on 10, 15 & 20 meters features 
improved boom to element clamping, stainless 
steel hardware, balanced radiation and a 
longer boom for even Avider clement spacing. 
Power Rating — 2 KW P.E.P. SSB. Recom- 
mended mast size — 2" OD. Wind Load — 120 
lbs. at 80 MPH. Approx. shipping weight — 45 
lbs. 5232.50 




CLASSIC-36 ... 10, 15 & 20 Meters 
Model CL-36 

• 6 Elements 

• 10.-1 dh Forward Gain (over isotropic 
source) on 15 & 20 meters, IJ.l db on 10 
meters. 

• 20 db Front-to-Back Ratio on ail bands. 
The Classic 36, like th^ smaller Classic 33, 
incorporates both the Mo'sley World-Famous 
Trap-Master Traps and the Mosley Classic 
Feed-System. Designed to operate on 10, 15 
& 20 meters, this multi-band beam Model 
CL-36, employs the high standards of quality 
constiuction found in all Mosley products. 
The boom-to-mast clamping as.sures stability 
with a time-tested arrangement of mast plate, 
cast aluminum clamping blocks and stainless 
steel U-bolts. The exclusive "Balanced Capaci- 
tive Matching" system has" a feed point 
impedance of 52 ohms at resonance. Wind 
Load — 210.1 lbs. at 80 MPH. Power Rating 

— 2 KW P.E.P. SSB. Recommended mast size 

— 2" OD. Approx. shipping weight — 71 lbs. 
via truck. $310.65 




CLASSIC-203 ... 20 Meters 
Model CL-203 
3 Elements 

• lO.l dh Forward Gain (over isotropic 
source) 

• 20 db Front-to-Back Ratio 
Incorporating the Mosley patented Classic 
Feed System, this full size 20 meter single- 
band beam has IV2" to 3/8" dia. "swaged" 
elecaents wide spaced on a 2" dia. 24' boom. 
Ma.\imum clement length-37' S'/i". The high 
standards in quality construction established 
by Mosley in over a quarter-century of manu- 
facttiring is reflected in this mono-band . . . 
Model CL-203. Boom-to-mast clamping 
assures stability with a time-tested arrange'- 
ment of mast plate, cast aluminum clamping 
blocks and stainless steel U-bolts. The exclu- 
sive ''Balanced Capacitive Matching" System 
has a nominal feed point Impedance of 52 
Ohms at 2 KW P.E.P. SSB. Recommended 
mast size-2" CD. Appro.^. shipping wt ; 42 
lbs. via truck. S227.65 



40 METER CONVERSION KIT MODEL TA- 
40KR 

Work 40 meters in addition to 10, 15 & 20 
meters by using a TA-40KR conversion kit on 
the radiator element of the TA-33 and TA-36. 
(Beams with broad band capacitive matching 
may not be converted!) Convert the TA-33Jr. 
with the MPK-3 (power conversion kit) before 
adding the T.'\-40KR kit. $92.25 



SIGNAL-MASTER ANTENNA 

Beam Antenna . . . Model S-402 (or 40 meters 

For a top signal needed to ptish through forty 
meter QRM. the Mosley Signal Master S-402 
will do the trick! This 100% rust-proof 
2-element beauty constructed of rugged 
heavy-wall alu^iiinum is designed and engi- 
neered to provide the performance you need 
for both DX hunting and relaxing in a QRM 
free rag-chewing session. Beam is fed through 
link coupling, resulting in an excellent match 
over the entire bandwidth. $267.50 



Tufts Radio Electronics • 209 Mystic Avenue • IWedford MA 02155 • {617) 395-8280 



Tufts Radio Electronics • 209 Mystic Avenue • Medford MA 02155 • (617) 395-8280 



Remote 



Motor 
Controlled 




^^^ 




1 


.\c 1 1 , 




QIH 


: 1 


^ 


i 


\ 




ii 




\ / 


■1 









COAX ANTENNA 
SWITCH 



• Control unit works on 110/220 
VAC. 50/60 Hz. and supplies 
necessary DC lo motor. 

■ ExceHent for single coax feed to 
mudiband quads of arrays of 
monobarders. The five positions 
alSow a single coax feed io three 
beams and two dipoies, of other 
simitar combinations. 

• Control cable (not supplied) 
same as for HAM-M rotator, 

• SeJects antennas remotely, 
grounds all unused antennas- 
GND position grounds all an- 
tennas when leaving station. 
"Rain-Hat" consiruction shields 
motor and switches, 

• Motor: 24 VAC, 2 amp. Lubrica- 
tion good lo — 40*F. 

• Switch RF Capability: Maximum 
iegal limit. Price: $120.00 



MATCHING NETWORKS 




Price: $120.00 



2000 walls PEP 

Price: $240.00 



General: • Irttegral Wattmeter reads foj^ward power in 
watts and VSWR directSy; can be calibrated lo read re- 
flected pov;er • Matches 50 ohm Iransmilter output to coax 
anlerina ieediine with VSWR ot ai least 5:1 * Covers ham 
bands 80 Itim 10 meters * Switches in or oul with front 
panel switch • Size: SV/'H, 10'^'W, B"D (14.0 X 27.3 x 
20.3 cm), MN^2000. ^Ali"D {36,5 cm). 

• Continuous Duty Output: MN 4, 200 watts; MN-2000, 
10OO walls (2000 watts PEPJ • MN-2000 only: Up lo 3 an- 
tenna Connectors selected by front panel switch. 



RF 
WATTMETERS 




W-4 

WV.1 



1.8-54 MHz Price: $ 72.00 
20-200 MHz Price: S 84.00 



fteacis forward and reflected power directfy in 
watts (VSWR from nomogram). Two scales in 
each direction. Size: 5;4"H, 3K"W, 4"D (14.0 x 
9,5 X 10-2 cm). 



Model Full Scale 



Calibration Accura^iy 



200 watts [5% oi reading -|- 2 watts) 

2000 watts ±(5% o! reading -h 20 watts) 

TOOwatts ±{S% ot reading + 1 watt ] 

1000 waits ±(5% of reading -r lOwatts) 



DRAKE 




S5R-1 



COMMUNICATIONS 
RECEIVER 



• Synthesized « General Coverage 

• Low Cosi • AH SoMd Stale ■ Built-in AC 
Power Supply • Selectable Sidebands 

■ Excellent Performance 

PRELIMINARY SPECIFICATIONS: • Coverage: 500 kHz to 
30 MHz • Frequency can be r&ad accurately \o beiler than 
5 kHz • Sensitivity lypicatly .5 microvolts for 10 dB S+N/N 
SSB and belter than 2 micfovoJls tor 10 dS S + N/N AM 

• Selectable sicieljands ■ Built-in power supply: 117/234 
VAC i 20% * It the AC power source taiSs the unit switches 
automatieally to an internal battery pack which uses eight 
D-cells (not supplied) • For recfuced current drain on DC 
operation {he dials do not light up unless a red pushbutton 
on the front panel is depressed. 

The parffjrmancG, versatility, size and low cost of tbe 
SSR-1 mal^e it ideal for use as a stand-by amateur of 
novlce-amatejr receiver, short wave receiver. CB monitor 
receiver, or general purpose laboratory receiver. 

Price: $35:0.00 



GENERAL: • All amateur liands 10 thru 90 meters in seven 

600 kHz ranges • Solid State VFO with 1 kHz dial divfsrons ^^^^^^^^mm^^^^ni^^^^^^^^ 

• Modes SSB Upper and Lower, CW and AM • Bmlt-in ^^^r^^^^^^^^^^^^^^^— ^? 

Sidetone and automatic T/R switching on CW • 30 tubes ^^H UJ^ 1 ^gLr^. jMlb- ^^~- ^ ' T 

and semi-conductors • Dimensions: 5y^"H, 1D*/S"W, ^A%" ^^K .fft M :^U' .^^fc "i^"" -.J 

D [14.0 X 27.3 X 3e.5 cmj, Wt.: 16 lbs. (7.3 kg}. ^^| i-.^::^ ^F ^^Pr ~ 

TRANSMIT: • VOX or PTT on SSB or AW • Input Power: 

SSB. 300 watts P.E.P.; AM. 260 watts P.E.P. controlled 

carrier cqmpatible with SSS linears; CW, 260 watts 4 

Adjustable pi- network. 

RECEIVE: • Sensitivity better than Vs ^V (or 10 dB S/N • 

I.F. Seleclivily 2.1 kHz @ 6 dB. 3.6 kHz @ 60 dB. • AGO 

tui] on receive modes, variable with RF gain control, fast 

attack and sidw release with noise pulse suppression • 

Diode Detector for AM recepiion. _ -. . —.^ ^ ., .^ ^^ 

Price: $699.00 TRh4CW SIDEBAND TRANSCEIVER 

34-PNB Plug-in Noise Slanker .... 100.00 

FF-1 Crystal Control Unit 46.96 POWER SUPPLIES 

MMK-3 Mobile Mount 7.00 AC-4 Power Supply $130.00 

BV-4C Remote VFO $1 50.00 DC-4 Power Supply . ■ ■"■ 135.00 




2 METER FM 

PORTABLE TRANSCEIVER 

Model TR-33C 



LINEAR AMPLIFIER 
Model L-4B 





Amateur Nest $229.95 

• SCPC* Frequency Control 

• 12 Channels with Selectable Xmtr Offsets. 

• AM FET Front-end and Crystal Filter for 
Superb Receiver Intermod Rejection. 

• Expanded Antenna Choice. 

• Low Receiver Battery Drain. 
•Traditional R. L. Drake Service Backup. 

• Single Crystal Per Channel. 



L-4B Linear Amplifier 895.00 

• 2000 Waffs PEP-SSB •Class B Grounded^ 
Grid - two 3-500Z Tubes • Broad Band 
Tuned-Input • flF Negative Feedback • 
Transmitting AGC • Directional Wattmeter 

• Two Tautband Suspension Meters • L-4B 
13-15/16" W, 7-7/8" H, 14-5/16" D. Wt.: 
32 lbs. • Power Supply 6-3/4" W, 7-7/3" H, 
11" D, Wt.: 43 lbs. 

POWER SUPPLIES 

AC 4 Power Supply t $1 20.00 

DC 4 Power Supply 1 35.00 



Touch'fi-go with 

DRAKE 1525EM 

Push Button Encoding Mike 



«££%,. 




Drake 1525EM, microphone with tone encoder and 

connector for TR-33C, TR-22, TR-22C, ML-2 $49.95 

• wlicropKone and auto-patch encoder in single convenient package with coil cord and 
connector. Fully wired and ready for use. 

• High accuracy IC tone generator, no frequency adjustments. 

• High reliability Digitran® keyboard. 

• Power for tone encoder obtained from transceiver through microphone cable. No 
battery required. Low current drain. 

• Low output impedance allows use vi/ith almost all transceivers. 

• Four pin microphone plug: directly connects to Drake TR-33C without any modifica- 
tion in transceiver. Compatible with all previous Drake and other 2 meter units vvith 
minor modifications. 

• Tone level adjustable, 

• Hang-up hook supplied. 



Tufts Radio Electronics • 209 Mystic Avenue • Medford MA 02155 • (617) 395-8280 



Tufts Radio Electronics • 209 Mystic Avenue • Medford MA 02155 • (617) 395-8280 




For all you hams with little cars ... 

* We've got the perfect mobile rig for you. % . - ^ Q^ 




The Alias 2iOx or 215x mansures only 
9>A' wiiie X 9V,' deep x only ai/i' hi^h. ^et 
iha tibfiVg phoiograph shows liow easily the 
Aiin^ Iransceiver tits into a compact car. 
And there's plenty of room \a spare for 
\'U¥ gear and othar accessory equipment. 
With liie exclusive Atlas plug-in design, 
you can s]ip ycur Atlas in anil tfal ol your 
cer in e melW of seconds. All rannoctions 
are made automaticsUi'. 

BUT DONT LET TH^ SMALL SIZB FOOL 

YOlJl 

Even though the Atlas 3iO» and ll^y. trans- 

ceiverE are le^ ihan lialf ihti size and 

weight of other HF transMlveya, The Adas 

is iruly a giant in performance 

2M WATTS POWER RATING! 
This puwer level in a sever, pnund irans- 
ceiver is incredible bu: irua. A'Jas trans- 
ceivers giva you all the talk power you need 
lo worl; the world barefooi. Sit^nal reports 



constantly reflect great ^urpri&kl fi [ the sig- 
nal Strength In relation to the power rating. 

FULL 5 rtANO COVERAGE 
The 2H)}t covers ll>80 meters, while the 
215x covers 15-160 meters Adding the 
Atlas Mudel lOx Crystal Oiciltatur provides 
greatly increased frequency cuvKrgge for 
MARS and network- operation. 

NO TRA-NSMTTTER Tli?JIKG OR 
LOADING CONTROLS 

wim Alias lolai braadbar.ding. Wirh yCur 
Atlas ynu pet instant QSY and'twnr; thiige. 

MOST AJDVANCED STATE OF THE ART 
SOLID STATE DESIGN 

r_Li; nnly ^.rcj^ip'^ ior its I^?Sl w?i:,'hl. but 
Si^crcs >rrj y5dre of :pp perif.irm:jr.i:e and 
iroubls free oper ating pletisjrc, 

PLUG-I^^ CIACLTr BOARDS 

and modular design provides Eor ease of 

servicing. 




PHE3V0MEV.\L SELECnVlTY 



9 pole crysJal ladlitr fii'e 
transceivers represems 



Tne e\ 

used 

ma;D: 

unpre-:' ....\ - ^'■■•-z: £e!t;c!'- ■*'■ ' ' :- 

limal"-' L. ■ ■ i^^trajC. ■ .^': 

thii " ■ " ■ ■ ? e 6 db :■- . |i .- 

2700 llur!.-. rJJ., i.'j Jcwn ri cnl^ AhiKl H*:ll, 

and a hnrjclnd-Ji of criv 933(1 Kvn a1 120 

db down; ILIltjnialB rejeclian iB in exCiCUS Ol" 

130 db; ;^ni:aier than the measurL:iK 'imits 

of rODsl te^l ennipmenl. . 



EXCEPTIONAL IMMUNITY TO STRONG 
SIGNAL OVERLOAD AND CROSS MOD- 
ULATION+ The exclusive front eod design 
in the receiver allows yau to operate cioKer 
in frequency (o strong neighboring signels 
than you have ever experienced before. If 
yoTj have not yet operated an Alias irans^ 
ceivBT in n crowded band and compared it 
with any olher receiver or transccivtl'. you 
have a real thriii coming. 







A WORLD WIDE DEALER NETWORK TO 
SEHl'E YOU, 

Whether yuu're driving a Honda in Kansas 
City Or a Merciades Benz in West Germany, 
tiiere's an Alias dealer near you. 

Arias liaK y. 3J,5x , . . $675,00 

W>Nnj^^ DUrnktl . . . , , Tlf>.y(J 

ACCESSOftrES: 

AC CfiTsanli- 110/^20 V S1-1V.(>(J 

Pc-rtL:il:>le AC fLi.pi>ly 1 10;220 V . 100. 00 

Plu^-in MnhiKj Kit , - -IR.OO 

I Ox Oil h-.^ tr>sl^5 51*. IIP 

Dig!:aJ IiiA\ UU-hB 22ft. 00 



For cjxpliIrE*^ i^p'afls &a6yQ'.ir Atlas dc.iier. 
CT dT'-i: us ;s i.^ir-1 and we'll mail yau a 
brcshure wiili dealer list. 

45^:^ ATLAS 

■\^^^ RADIO (NC. 




AMATEUR 
ANTENNAS 



'the home of originals" 



SUPE^ ^AJN MOBILES 
Two Msters 



' 3.2 d: ie; 



.fl/4w 



STANDARD GAIN 
rwKD BILES 
Two Meiers 

fluar 1/4 waveriiObiie 

■ Kn-au*nty MJerage— 113 to H9 

MHj 

■ Po**i rating— 20O warts FM 
MODEL BQLT-IM 

a;' anlen^a torrplete with eatv 
to injtallH no holes I* tirlH, irunk 
hp mOunl, impact spriri; and 1?' 
MIL SPEC T?fr5S-U ana PLK9. 
Ank-nna fernsrable tiom nOLihl 

PriM: S33.75 
MOO^L BSL-144 
tr anicr.nfl FiiaLnts on any Sir. 

iwp^s i" 

ir i^'i^ s=EC Ri3^=3-l: 

t"i-!tr.Ti3 r?-rr.[^.'at'-e (■l.r n:""! 

HUSTLER 

" BUCK- BUSTER" 

MODtL SF-1 



^ rig*— 1*3"!^ 



51 f»; n-ei 



Mienna 
■ S'licuc'^cy ctn 

- SWR at fesena 

TWO OMO 511 METERS— [s- 

TRU^« LIP MOUNT "^ 

MODEL HFT 

Foiir wet^on lelescQ[iic anlcnn? 
DsimJts separate ga|UiTnwni (or 
simuitaneOuJ resorLante on two 
and 5fK meters Oporijtional 
heiEht: -lir. Complftte with trjrh 
Up mount, XT MIL SPEC fiG-SS-U 
and factory &tlacii«J PL-?5V. 

PricE; $2^.65 

VHF;UHF AMTEt^NA— 

ROOF MOUNT 

WUDEL 'JHT-I 

T'Hif ""LTvrabH f«a.<kv *x l,-1 

rrviAjd€4. HanlL ar irfr til ii.v- 
!iii)#. nA^. «^*, tt*«* in ^t~ 

Pri«- S9.W 

I i 



HDDEL CGT-1U 



pi -I 



ni 



S.V M|I''>4v A.-ivTn^ E^ KitiM^ 
__L_ _n iJ^ Bi *4* r^ Vinti ;+(. 

-■ Tr.sJ^S|JJ»^cM^^B 
lC*: $41.30 



IT «', 5-*r.'. 



AJ 



ii--i4 C2<N :. Ill 

3 wfl* i* - ■ r 

sr Kiitr*' mobile rn ris 

fWnun! or «b[e not 'n' -J^d! 

Price: $^.00 

DELUXE MOBILE MOUNTS 



li 



I 




RESONATOR SPHIWG- 
STAINLESS STEEU 
MODEL RSS-2 



i) 




ci>!ss 17 ftO-SSJ ton. 
Pr:u:Sl4£5 



Ci*iiMe !i jil" lip mob 



MOML GCH-1 

! Hair ;iitte^ t^jd! ■'lii 

I lii s!M3e5, SrtS'^i err. 
ilfs: triTn l-:"e g-ytlKri 

ta. Pr^MiSaOO 




MODEL MH-I 
Cowl mounl tr^talls in 
r nolo. Includes ISO" 
iwJvcl ball and SD-239 
tonnflCtOiS, 
Prico: $750 




MODEL TCM-I 



tn»vc under injnk lid 
ItiUntrng hardware in- 
t:iiMJed, Prito: sa.QO 



MODEL C-3r 
Gall mount complete 
Willi mounting hflrdf^ai?- 
PricB: £9.20 



MODEL CG-1M 

Sarr«- cnj-mtftf^ilits as CGT-14-1 
■S-uPpi *rt with ^f'-JJ -tia-se to 'It MJ 
mobtk ball nir>unls — Lengtti is 
B5 " Mount jnd caWe nor in- 
cluded p,(c^. S2S^o 



VHF/UMf ANTENNA— 
TRUMK LIP MOUNT 
MODFL THF 

Field (!!mr!iEJ« r^Jialcv^ pemsii-s 

tfv.u^aty TtttT, tt@ ;C' 5«1 »Hz 
C^ni Art i-;-;id!Ed. C*"^?*!* 
mirn r*-j^ I B Tis.iT 37 RG-JE-U 
and F^-MS p.,«:Sie.S5 



STAINLESS STEEL BALL MOUNT 
FOR DECK. FCHDEF9 DR RKT 
FLAT SUWfftCE 
MODEL ^iM-2 



QtJiCK □lECOHNEr.T— 
1«% STAINLESS KTEEL 
UODEL 0D1 



All xesoiiators are precision wovmd with 
optimized design for each band. Assem' 
bly includes 17-7 PH stainless steel 
adjustable tip rod for lowest SWR and 
band edge marker, l^oose for medium 
Or high power operation. 

STANDARD HUSTLER RESONATORS 
Power Rating: 400 Watts SSB 



Model 
flM-10 
RIVl-15 

avi-20 

RM-SO 



Band 
10 meters 
15 meters 
20 meters 
40 meiefs 
75 meiers 
80 mHters 



Price 
S 6.50 
6.95 
7.30 
13.20 
15.50 
15.95 



^ 



i 



SUPER HUSTLER RESONATORS 

Power Rating: Legal Limit SSB 
'^ Supers havo widest bandwidth 



Model 
RM-10S 
RM-15S 
RIVI-20S 
RM^JOS 
RM-75S 
RIW50S 



Band 

10 meters 
1 S meters 
20 meters 
40 meters 
75 meters 
SO meters 



Price 
S1 1.30 
12.65 
13.00 
15.&0 
30.00 
30.40 



For 6-10-15:20-40-75-SO Meters 



•tTiZjl H.Si i"sVep'-:«J i-^fi't -.'u'.ci'. 

hds W-Zt IJneatft 10 M (noti'e bai 
MODtL MOZ 



HUSTLER 
MASTS 



The MiJDnijr Ct^c-i» oi 
Throughoul the Wnfld! 



MODEL MD-1 

Fof deck or fender rttijunii'ig— Fold ;s 

al Fwf line 15' abow tjasc. PfLe&:S22,00 

Covers 10 - 15 - 20 - 40 Meiers 

Dniir HuHlir Givai Dm ttV.mt *tn 

WhDia Kand Carani* 



1 




Ptim: S6.S5 
imIdde._ ai-^-i4Ji -- bctLi* T-Ji 

r i*J ^UliO'l Eptfi^qr. 6 it. gam 



-1^4 V-i^aveur^ r.^raon HsiEt-1 117" 

/Tff SWH jl ri:,-.. LiiK-p 1 2 : Oi beltct 

/I j PDrtcr rai-nc, I.MO WsHs FM. w^na 

•T CE-1<^ 



lOO MPH, 
prpf up 
r «nn«l 



," O.D SO £39 
Prica: SS7.55 



KO-1 
MDl 



MODEL 4-BTV 

■ ■_£»*« S'rtft— PLLS 

- Bardwlatn a: iii brsarm! Srtfl 
:.£ If ^ tr QeHer ai tanej erge* 

~ii--a: ■>:-.'.'^ "O ;lh*r«iSe Lr- 

inf »:::in« »rd perrrjT?e-il trap 

chunical ilxtMlily. 

- E;rtra hoKy duly sfuirti.njm jpojii;- 
ii^ br3f:k;t ^itn law bii — high 
st^e'PBt^ ir«Lilalon Moimting h^ard- 



■ £tai-;tss 

B tn n.n ii.D rg 

■ Guarartccd [3 b* f^i-ifs! sJse^nQiij 
of a"! ni.i'. -ajrid i*r:i 

- Jl^ten-a pui **"-;4 iljd al l:^f" ^- 



n Ell"rf 



= '•?*<!■ 






alL. I 



Feed iiifh any itnuih W Dhrr 
Po«r taM^iiiRr— lull tega 
an SS& or CW 
■ MaunLiDg: Qiaitnii mounl wJth or 
v^ithout raili:iK, □' rwP mo 
radiials. 

Weigllt: 15 Ib5, 
Pric«: 599.95 



itH 



Tufts Radio Electronics • 209 Mystic Avenue • Medford (VIA 02155 • (617) 395-8280 



Tufts Radio Electronics • 209 Mystic Avenue • Medford IVIA 02155 • (617) 395-8280 



Super Amp 

from Den/roTL. 




If the amplifier you're thinking of buying doesn't deliver at least 1000 to 1200 uvaltg nulpul, 

to the anrer^a, yoti're bMying the wrong arTtplifrer. 

Our New Super Amp is sweeping the country because hams have realized Iliat the DenTron 

Ampflfier will deliver to ths antenna, (output power], what other marufacturers rate as input 

power. 

The Super Amp runs a full 2000 watts P.E.P. input on SSB, and 1000 watts DC on CW, RTTY 

or SSTV 160-10 meters. The tnaximjm legaS power. 

The Supe: Amp is compact, low profile, ha; a solid one-piece cabir^et assuring maximum TVI 

sheilding. 

The heart of our amplifier, the power suppTy, is a continuous duty, self-contained supply built 

for contest performance. 

We mounted the 4-572B's, industrial workhorse tuties, in a cooling chamber featuring the 

on-demand variable cooling system. 

The hams at DenTron pride themselves on qiialit/ work, a,nd we fight to keep prices dowr. That's 

why the dynamic DenTron Lin&ar Amplifier beats them all 

$574»S0 

Th£ 80-10 SUytnateher 

Here's an antenna tuner for 80 through 10 ineterE, handle? 500 w P.E.P. and matches your 
52 ohm transceiver to a random wire antenna. 



- Continuous tuning 3.2 ■ 30 mc 

* "L" network 

- Ceramic 12 position rotary switch 
' SO— 239 receptional to transmitter 
■ Raiidom wire tuner 

* 3000 vok capacitor spacing 

• Tapped inductor 

• Ceramic amentia feed thru 
' 7" W. 5" H. S" D., Weight: 5 lbs, 

$59.50 




Read forward 
and reflected 
watts at the 
same time 



Tired of constant switching and guesswork? 

Every serious ham knows he must read both forward and reverse wattage simultaneously 

for thgt perfect match. So upgrade with the DenTron W-2 Dual in line Wattmeter. 



Match everything from ibo to 10 
with the new I60-IO MAT 



NEW: The Monitor Tuner v/as designed be- 
cause of overwhelming demand. Hams told 
us they wanted a 3 kilowatt tuner with a 
built-in wattmeter, a front panel antenna 
selector for coax, balsnced line and random 
wire. So we engineered the 16Q-10m Monitor 
Tuner. It's a lifetime investment at $299.50. 



$299.50 




Meet the 
SuperTuner 



The DenTron Super Tuner tunes everything from 160-10 meters. Whether you have 
balanced line, coax cable, random or long wire, the Super Tuner will match the antenna 
impedance to your transmitter. All DenTron tuners gtve you maximum power transfer 
from your transmitter to your antenna, and isn't that where it really counts? 



1 KW MODEL 



$129.50 



3 KW MODEL 



$229.50 



The Shy 
Opetters 



\ 



SKYMASTER 

A lully developsd and t«ttKl 27 fam _ 
'/ertical antenna covej-i entire 1 0, f 5.' 20, 
and 40 meter bands using orJy one ctevarly 
\]pplied wave trap. A+uH 1/-! waveantemia 
on 20 matBrf. Ca^istructed oi hsauy s«an\- 
Igs! aluminum with a factory tunBd and 
scaled HQTrap, SKYMASTER H wcathor- 
pi-OOt and wkhsTands. wind;: up to SO nph. 
Kandl&s 2 KVJ ptjwur \nvei and is tor 
ground, roof or to^er mourttins. R^diaU 



£ 



iTiCli^ded i( 






$84*SO 



f\ resonBior for top nounting c 



SKYMASTEB. 




$29.50 



TRIMTENNA 

"FliB antenna yaur naiglihors will lOve, The 
new DsrtTtiJii Trim-Tijnna with 20 mater 
bearp U designed tt>r tliB disciimEnating 
amatcLJi' who wants fanlsatfC psiformartca 
in an environin^n tally appealing b^^in. h'i 
reallv Ifladed! tJp front thers's a 13 toot 
6 inch director vjith precision Hy-Q coils. 
And. 7 feel behinn:! h a 16'fnBt driven 
oSement fed directly railli 62 ohm coax. 
The TrJin Tenna mount* easily and what 
a diHerence in on-the-air psrformance be- 
tween the Trim-Tenra a^rf that dipola, 
iong wire oj inserted Vee youVe be&n 
using. A &t & foTward Gain Over Dipole. 

$229.50 



SKYCLAW 

A tunable monabard hi^gh p-arfoftnance 
uarrical antenna, designed tnt CO.&O, 160 
malar operation. SKVClJ^W giues you 
the fotJpwing spectrum covarage: 
BAND BANDWIDTH 
{Met&ril tkHT) 

160 50 

30 200 

40 entire JMnd 

Tuning i;: aasy ^fi'^ ceiiable. Rugged con- 
slruction assures that ihij self-supporting 
unit i; w^athsiproo'! and survives nicely 
in 100 mph vimds.. liandEcs tuli kgal 
powor limit. 




$79.50 



$99.50 



EX-1 

The DenTron eX-1 Veriiwf Ani&mia is 
designed for the pertormancs minded 
antenna eKper\K\entsi. The EX.-1 is a full 
40 meter, Vt wave, 33', isnlfiupportlng 
iiBrticBl. The EK 1 is the idesf ve<tl(;al 
(or phaiinj. 



$59.50 



ALL BAND DOUBLET 
Jtiii All ^nd Dojblot or invert&d Type 
Ant&nrtB covers 160 thru 10 meters. Haj 
total \ength &f 130 teat (14 ga. Jtianded 
copper! althoygh it may be made shofter 
tf necexsary- Tliis tuned Doublet is ccTiter 
fed through 10D feet o1 4S0 ohm PVC 
cove-red b^anced transTnissinn liTia. Th« 
assembly is corrplete. Add rope to the 
erdr and puEl up into poiit'on. Tune 
witii tiic DenTron Super Tuner and 
you're on lO tjiiouijh 160 mttcrs-with 
one antenna! Now juit tor the DSTiTron 
All Band DowblBS. - 

$24.50 



DenJfon^ 



DRAKE TVI FILTERS High Pass FUters for TV Sets 
provide more than 40 dB attenuation at 52 MHz and lower. 
Protect the TV set from amateur transmitters 6-160 meters. 



Drake TV-300-HP 

Model No. 1603 

For 300 ohm twin lead 

Price: $10.60 





Drake TV-75-HP 

Model No. 1610 
For 75 ohm TV coaxial 
cable; TV type 
connectors installed 
Price: $13.25 




DRAKE TV-3300-LP 

1000 watts max. below 30 
MHz, Attenuation better than 
80 dB above 41 MHz. Helps 
TV i-f interference, as well as 
TV front-end problems. Price: 
$26.60 Model No. 1608 



LOW PASS FILTERS FOE. TRANSMITTEKS 
have four pi sections for sharp cut off below channel 2, and to 
attenuate transmitter harmonics falling in. any TV channel and 
fm band- 52 ohm. SO-239 connectors built in. 

DRAKE TV-5200-l,P 

200 watts to 52 MHz. Ideal 
for six meters. For operation 
below six meters, use 
TV-3300-LP or TV-42-LP. 
Model No. 1609 Price: $26.60 

DRAKE TV-42-LP Model No. 1605 

is a four section filter designed with 43.2 MHz cut-oft and 

extremely high attenuation in all TV channels for transmitters 

operating at 50 MHz and lower. Rated 100 watts input. Price: 

$14.60 







Tufts Radio Electronics • 209 Mystic Avenue • Medford MA 02155 • (617) 395-8280 



Tufts Radio Electronics • 209 Mystic Avenue • Medford MA 02155 • (617) 395-8280 

WORK ALL REPEATERS WITH OUR NEW SYNTHESIZER H 



i». 




KX3sr W/T . 
HXSOC Kit . 



RXSOC W U 
RX134(.- Kit 



KXIl-K." V.'. T 
RX3:oc Kii. 



KX230f W.T 
KX4J2f K:i. 



RX4.nC Wi'T . 



TXSO . ■ ■ 
TX50 W/T . . 
TX140B Kit . 
TX144B W/T 
TX220B Kit . 



PA250JH Kit 



PA 2501 H W.T. 
PA4010H Kit . 



PA4010H W/T. 
PA SO,' 2 S Kit . 



PA50/2; W/T . 
PA14ili!S Kit . 



PA 114/25 Kit . 
PA 3 20/! 5 Kit . 
PA432/10 Kit . 

PA)40/10 W /T 
PA I 40/30 W/T 



28-35 MH/. I M /i.-i;eiver with 2 
pfjie 10.7 MH7 Liyslai fillet . , . .S 59. ys 

^lamc dS :ih<3Vt: -^^■ired &: ttfstuil . 104.95 
311-60 MH/ rcvr w/2 pule Ifi. 7 

V;H/ trysljl filler 5<)-15 

same u^ ;ihtjvt -wired d( iL'vlrJ . . 104.95 

1 J(l-I 70 .MH/ rivr iv/2 polt 

10.7 MH/ cn.ital filter t9.<*5 

slime ^s jbti'.'e •.■.■ire.ii &: tL-\;i-d . . 114.95 
210-2-10 MH/ rvvr iv,'2 prjk- 

10.7 MH/ crystal filter r9.95 

^jme Its lllio^e-wsred & Tested . . 114.95 
432 MH/ n.vF is-'2 p. lie 10.7 

MHz urvsial filter 79-95 

•isime LIS Lihijve-wired Ai tesl^'d 124.95 

transmitter exciter, I watt, 6 m:r. 39.95 

same a.s above -wiiu;d ^ tested . . 59. 9S 

transmitter exciter- 1 waTt-2 mtrs 29.95 

same as above— wired & tested- . . 49.95 
transmitter e:(citer— Iwatt — 220 

MHz 29.95 

2 mtr power aiiip -kit l^v jri- 2 5^v 
out with solitJ suie .switching. 

case. Connectors 59.95 

same as above— wired i tested . . 74.95 
2 mtr power amp — lOv,- in-40\v 

oiit-rclay switching 59.95 

same as above --A'ired & re-=;ted . . 74.95 

6 tntr po^ser amp. I w in, 2 5sv out. 

less case, connectors &. switching ■ 49.95 

same as above, wired & tijsted - . . 69.95 

2 mlr power amp — Iw in — JS^s' 

out— leS-=; case, connectors and 

switching 39.95 

same as PA 144/! S kit but 25w . . 49.95 

similar to P.'\144/15 for 220 MHz 39.95 
power amp-similar to PA I 44/1 5 

except 10wand432MH/ 49.95 

lOw in^]40w 091-2 mtr arnp . . 179.95 

30w in -I40w out-2 mtr amp . . 159.95 



HSlSCW/T 
PS2SC Kit . 



PS;5CW,T . 
PS2SM Kit. . 
PS2 5M W./T . 

RPTSO Kit. . 
RPT50 .... 
RPT144 Kit . 



RPT220 Kit . 

RPT4 32 Kit . 

RPT144 W/T 
RPT320 W/T 
KPT4J1 W/T 
I3FLA50 , . - 

TKXSOKil . 



TRX144 Kit 
TRX220 Kit 
TRX4 32 Kit 



TRC] . 
TRC-2 . 



SYN [| W/T 
MO-1 Kit. . 
TO-1 Kit. . 



HT 144B Kit 

NICAD. . . . 
BC12 .... 
Rubber Duck 



I £ amp- 1 2 volt regulated power sup- 
ply w/case, w/fo!d-back current limit- 
ing and overvoltage protection . . 79.95 
same as above-wired & tested . . 94.95 
25 amp— 1 2 volt regulated power sup 
ply w./case. w/f old-back current iimit- 

ine and ovp 129.95 

same as ahove-^vired i Tested . . 149.95 
same as PS2 5 C with meters .... 149.95 
same ii.s a bov</ -wired &. tested . . 169.95 



repeater- 6 meter 465.95 

repeater-6 meter, wired & tested 695-95 
repeater — 2 mtr-l 5w— complete 

(less crystals) - . . 465.95 

repbateF-220 MHz — 1 3w— complete 

(less cry.^itais) 465.93 

repeater-l watt -432 MHz 

(less crystals) 515-95 

repeater-lS watt-2 mtr 695.95 

repealer-15 watt-220 MH-,^. . . . 695.95 

repealer - 10 watt— 432 MHz. . . . 749.95 

6 mtr close spaced dupiexer . . . 575.00 

Complete 6 mtr P"M transceiver kit, 
20wQut. 10 cbannel scan witJi case 

(less mike and crystals) 749.95 

same as abovp. but 2 mtr &. 1 5w out2] 9-95 
same as above except for 220 MH; 219.95 
same as above except 10 wjtt and 

432MH7 234-95 

Transceiver case only 19.95 

transceiver case and accessories . . 39.95 

2 mtr syntliesizer, transmitt offsets 
programmable from 100 KHz-lOMHz, 
(Mars offsets with optional 

adapters) S69.95 

same as above— wired & tested , . 239.95 

Mars/cap offset optional 2.50 

IS MHz optional tripSer 3.50 



2 mtr. 2w, 4 cnannel, hand held receiver 
with crystals for 146.52 simplex. . 129.95 
bsliery pack, 12 \'DC. l-iamp. . . 29.95 

battery charger for above 5.95 

2 mtr, w-iTh male BNC connector . S.95 



The Synthesizer II is a two meter frequency synthe- 
sizer. Frequency is adjustable in 5 kHz steps fiora 
140.00 MHz to 149.995 MHz with its digital readout 
thumb wheel sivitching. Transmit offsets are digitally 
programmed on a diode matrix, and can range from 
10 kHz to 10 MHz. No additional components are 
necessai'V ^ 
Kit .....'..., $169.95 Wired and tested$239.95 

Also available for 220 MHz! 

accessory filter for above receiver kits 

T^ives 70 dR adjivcent channel 

rejection . . ". S.50 

1 mtr RI frunt end 10.7 MHv out 1 2.50 
6 rr.Ir RF Jroiit end 10.7 .MH/ out 12.50 

2 n-.tr RF front end 10.7 .MSiz nut 17.50 
220 MHz Ht iti.nt end 10.7 MH/ 

out - - 1^.50 

43; MHz Rl Iront end 10.7 MHz 

out 27.50 

iO.7 MHz IF module includes 2 

pole crystal filter 27.50 

455 KFIz IF stage plus IM deleciur !7.S0 

audio and SliucIcIi board 15.00 




TR.4,NS.MITTERS 




RF2S Kit . . 
RFSO Kit . . 
RF144n Kit. 
RF220n Kit . 

RF432 Kii. 

IF 10.7t Kjl 

FM4S5 Kil. . 
.\S2 Kit . 

TX220B W/T 
TX4J2B Kit . 
TX432B W/T 
TXI SO Kit. . 
rxi SO W/T . 



POWER .AMPLIFIERS 




^ame as al:>o\e-\^'ired &. :esii;d , M 9,9 5 

(rartsmitter exciltr 432 MIJz ■ . 3<J.9S 

same as above— wired & tested ■ - 59.95 

JOO milliwaf [. 2 niiir transmitter ! 9,9S 

SHnie as abovt: wired &. tested . 29,95 



RI- pf>i.ver ^mp, wired & tested, emission — 
nV-FM-SSB/AM 

F'ower Power 

treque^icy Input Output 

45- 55MH2 .nv iSOW TBA 

I40-i60MH2 low 70W J 39.95 

140-1&0MH2 ?W low IS9.9S 

KO-l^OMHs JOW I50W 359.95 

140-160MHZ 30W I SOW 239.95 

220-2 JOMHx 2\V 60W 1 59.95 

220-23OMH2 lOW 60W 139-95 

220-13OMHJ low 120W 259.95 

420-470MH^ low 40W ] 39.95 

420-470MH:^ 2W 40W 159.95 

420-470 MHz 30W 80W 2 5 9.95 

420-4701^1^12 low SOW 269.95 



adds over volia^t pmteciib'iTifi vitur 
pox'.er supplies, 1 5 \'DC ms\. . . 9.95 

1 2 \olr-puwLT sjppiv regulator card 
with fotO-baL-k ojrrent limiting - . H.^^^ 
new conimercial duly 30 amp I 2 \']}C 
reeulatud powt-r supph Wj-ca^v, 
wyfold-hatk current limitinsand 
o^'^r^'olI3g^ prutcctior: 2-^9.95 



^^liiiiliiii*^ 



REPE.^TERS 




DPLA144 
DPLA220 



DPLA432 
DSC-IJ . . 



TR.\NSCEIVERS 

^ i m iiiw " 

SYNTHESIZERS 



WALKIE TALKIES 



OTHER 

CDl Kit - - 

CD: Kit . . 

1.11.1 Kit - . 

a)Kj K!\ . 

SfJ Kit . . 

Cr\ stills . . 

CWIIJ Kit . 



OVID 
CWID 
MIC 1 




TSl W;l . . 
TSl V,-/l . . 

rnj xii . - 
rn.i V. :\ 

HL144 W.'T 

HL220 W.I 
HL432 W 'I 



2 mtr. fiOO KM/ spaced duplei^er. 

-.vjred and tuned to fretiLieniy . . , 379.95 

220 MHz duplexcr, wired and 

tuned Itj frequency .179.95 

raclt mount diiplexer ^19,95 

double shielded dupie.^er cables 

wiih l>L259 connectors (pr.) . . - 25,00 

SLime as iihuw- willi type N 

connectors (pr.) .,..-.. . 25.00 



PRODUCTS BY VHF ENGINEERING 

10 i;h^nnL-l rtcriv^ x t j] ijeok 

Wr'diude s^vjtchiiig i f).95 

. . 10 channel vmt deck \v;5;wi'.„-ti 

and irinimcr.^ 14.9? 

, - UHFv^rsiiin of rUi ue.k, iu-^.-.l- I 

-fur -431 r(ulli-jf:nuit:l 'iper;i: !L.r_ j 2.Q5 

■L'urTter c5perLLtL' J r\:^Li y , ... |9.Q^ 
10 channel ,t jk;-sc;im udapLer 

lor KX wirl-k priority I9.9.S 

. . we stock most repeater iind ^implex 

pair.s from i4ft. 0-147.0 (each) , S.OO 

. . 159 bit, field proi^raiiimable, cotle ideit- 
tit'ierwith bud[-i[^ squolch l;til aiul 

in timers J'J.^^S 

wired !ind tested. iKjt prograiTiiiied 5'1.95 

«iTed "Jiid tested, progxainmtrd ?'J-95 
2.000 fliiii Ll\:i.imic mike ".vilh 

}M.l. jiid (.oii -ord .... I 2^^ 

L-.ne Svjuekl; il.j^.idef 59. -J?. 

ii]>{aik"i.i SI"* repL'j',i.'r, n^^lj Jms: 

i];"ierfjce a^'i.ess(ir;-^ ... - S-'.k'5 

2 i5)]ir d^ci.iJer 2 > fS 

sjmc J^ :ibiiV, w ired ii T^.^l.^C .^9.95 
4 piilr he,iii.':il r-j''i'--i:u[i>r, v.;r.^dA^ [■L\:id. 

?i\\ep5 :jijed i-: ,-44 MM'' h^n :-; >^ 

sjirn; j^ jhu\ I- ii!i:ed U- 21'"} %' I i / i\yi ?■; 9? 

vjfEii; .!> ^h'H'e riiitecj i" -i.i2 MH/ h.ci. ;;-i.9^ 




hf enaineering 

THE WORLD'S M.OST COMPLETE LINE OF VHF-FM KTTS .«JD EQUIPMENT 



Dealer Programs 
NOW Available 



Tufts Radio Electronics • 209 IWystic Avenue • Medford IVIA 02155 • (617) 395-8280 



Tufts Radio Electronics • 209 IVlystic Avenue • Medford IVIA 02155 • (617) 395-8280 



KLM RF Power Amplifiers 



'ADDON 
FOWER! 



KLM 



PVeirmaNrca 



WATT6 

LINEAR 



• A simple, add-on-immediately 
RF amplifier. 

• Merely coax-connect amplifier 
between antenna and transceiver. 

• No tuning! Efficient strip-line 
broad band design. 

• Automatic! internal RF-sensof- 
confrolled relay connects amplifier 
whenever transmitter is switched on. 

Highest quality. American-made "brand" 
transistofs are fully protected for VSWR. 
short and overload, reverse polarity. 
Highly etf&cliv^ heat sinking assures long 



Manual, remote-positron switching 
is optional. 

• Models for 6,2,1 'A meters, 70CM 
amateur bands plus MARS coverage. 

• Two types: Class C for FM.'CW. 
Linear for SSB;AM./FM/CW, 

» Negligible insertion loss on receive. 

• American made by KLM. 

life, reliable pe^formsnce- Slack aoodized 
containers, .exclusive KLM e<trusit)ns, 
have seven, full length fins on 
both sides! 



FBEO 


MODEL 


FWHINR 


KOM. pwn 


HDM.Cun. 


SIZE 


PflIM 


.FREO. MODEL 


pwn iKp. 


NOM PWR 


NOM. CUR. SIZE 


PRICE 


FREO. MODEL PWH INP NOM PWR 


KDH. CUR. 


SI2E PRICE 


,.M"?I 


NUMBER 


>3;rsi 


OUT, -i-'S 


iSmps ir 






.VH;- NUMSEn 


*var5 


0UT:«r:E 


'smps )T 




MHz.i NUKBER i»j(!5i OUTiwallsl 


iimps iT 




50-5C 


PAi SOSL 




K 


■OA 


c- 


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144-14S "tMi-i:"- 


i IS 


if; 


1^ c- 


159 95 


•JX'-iTO PA2-4aC '-4 JG 


- 


C- 149 95 


i;4-KS 


P4?-!29 


' i 


12 


J 


H 


59 95 


=iiOi.. 


MS 


i4r 


IS 0- 


199 95 


"A'C-JSC 5--5 35 


t: 


B- 119 35 




PA2-70B 


1.^ 


rc 


■■!! 


c- 


:55 95 


=A •,:■■, J,;,:. 


^. ' ■. 


lie 


15 0- 


215 95 


PAl^JSCL ■ S-'5 36 


E 


i- 139,95 




FAJ.7G3L 


■ 4 


70 


'G 


f 


IBS 95 


PAIO-ia^L 


r '7 


■^L■ 


22 C- 


2M.95 


9M0-HX, 5-lS 71; 


13 


[i- 229 95 




PSMJCd 


;-4 


■JO 


:a 


z 


229 95 


pAsj-oa 


15-41 


■40 


li D- 


1F3,95 


PA-O ?CC_ 5-lS 7C 


■s 


[>■ 249 95 




PA-C-aOB 


=■55 


40 


5 


fl 


63 55 


=;32---,;HL 


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■43 


i; 3' 


19S95 










PA-C-40EL 


: ;■■; 


40 


5 


3- 


94 ?= 


2-9-226 PA?.7fBC 


-.4 


70 


IC C' 


165 35 


SIZES: iBOSBl: "A, J ?5. j ■ ^ ■B.t E-a.? 


C * i - .• 5 ■ 


■0.5 s-:;-; 




PAIC 7CB 


5 1: 


:q 


8 


"y 


139 « 


"A-j-ecBC 


5-'5 


6-: 


a c 


149 95 


MM: 57.i;7.i:B ■■'5.I?7.55S 


f5.^5Q.l.a 


• 16;- 2S;.5CS 




pa: C- 756 


Ti -S 


70 


S 


c- 


149=5 


=*3;--?risc 


15-4i 


'2il 


15 3- 


-,S9.5S 


LlKEARAHPLinEB TAl 13.5VDC. 







TEMPO 



Dealer Programs 
NOW Available 



ATLAS 350-XL. 




• ALL SOLID STATE 

• SSB TRANSCEIVER 



• 350WATTSP.EJ>. OR CW INPUT 

• 10 THROUGH 160 
METER COVERAGE 




THE TEMPO 2020 



h Phase ICL-k-ijop tPLl.) o;,*:il."i!rr- siituil mnimijcs 

un,wan[efj saunijus rc-,fionsi''5 
h HybriC DigiliJi F^jqueniy Pre^tffM'.iin 

I Biji!l-(r AC ar.n M VDC povs^r e^iippiies 

I CW [fife. 5[9-:^s:7 eq,iipn-i-?i' nci a- .icct5S^.-y. 

e.]tj!p"i^r- ..no! ^- a.^-ressriy 

> Bl.;!:- - VO/ anri Mm -^-^il' CW kfiyirvi 

. C^Sia' Cadnralcr ^-fT ".W^V '■i-re-'. n^ ziL-sT,- -.:■,. 

h D.ai PIT COtI'OI aii;ii;5 COTn t'OSfl 3r7C f«ircw 



. vlu::i-ncd5 USB. LSB. CW gic AM op^ratian 

• ExIracTdinary 'Bc^iver scf^iiHwily [.3u S'M lO Cbl 
ancosciilatof^iab-Ji^vnCO HiSOrrrJ-. a'lcr wafT-up] 

• PiXfKl cnsrrtel crystal c?''Toi <;n iwo dvaiifi^lc 

pOSill04t3. 

• E-i(T--^ scsake- 

• The T=K'=0 3C23-S759-K- 

• Wlooe a-M estsuva s^waite . .aS^.S:. Mctic fi^iO 



::sr-d 50 Ihro-jti ^G r 



TEMPO 

VHF/ 
ONE PLUS 




Illustrated with 

optional AC supply. 

Auxiliary VFO, and 

Digital Dial. 

The aJl new Atlas 350- XL has all the exciting new featiu'es you 
ivant, plus supeiiot performance and sfelectivitv control never before 
possible. Price: $995,00 

• 10-160 METERS 

Fidl coverage of all six amateur bands in 500 kHz seginerils. Prioiary 
frequency control provides highly stable operation. Also incUided-is 
provision for adding up to 10 additional 500 kHz .segments between 
2 to 22 MHz by plugging in auxiliary crystals. 

• 350 WATTS - - ■ 

P.E.P, and CW inpiit. Enough powder to ^vork the world barefoot* 
IDEAL FOR DESKTOP OR MOBILE OPERATION 
Measuring just 5 in. high x 12 in. wide x I2V2 iir. deep, and weighing 
only IH pounds, the Atlas 350-XL offers more features, perfor- 
mance and \'alue than any other transceiver, regardless of si'.?e, on 
the niarltet today! 

• 350-PS matcliing AC supply — SI 9 6.00 

• DD-6XL plug-in digital dial readout S195.0O "* 

• 305 plug-in auxiUary VFO — §155,00 

• 311 plug-in cirsstal oscLUator — S135.0O 

• DMK-XL plug-in mobile mounting kit — S65.00 



^^^^^£^#^^dSU.4^!gM 



The Tempo/ONE PLUS offers ful) 25 watt outpu! or a 
selectable 3 to 15 wait iow power output, remote tuning 
on ttie microphone, sideband operation with the 
SSB/ONE adapter, MARS operation capability, 5 KHz 
nurnerical LED, and all at a lower price than its time tested 
predecessor... the Tempo VHF ONE. 

The Tempo VHF/One Plus is a VHF/FM transceiver for 
dependable communication on the 2 meter amateur band • Full 
2 meter coverage, 144 to 148 MHz for both transmit and receive 

• Full phase lock synttiesized (PLL) • Automatic -repeater split 
— selectable up or down • Tvuo built-in programmable channels 

• All solid state • 800 selectable receive frequencies with 
simplex and +600 kHz transmit frequencies for each receive 
channel. Price: $399.00 




TEMPO ONE HF Transceiver. 80-10M. USB, CW & AM - $399.00 
AC/ONE Power supply for TEMPO ONE - $99.00 

VF/ONE External VFO for TEMPO ONE - $199.00 

TEMPO SSB/OME 

SSB adapter for the Tempo VHF/One 

■ Selectable upper or lower sideband. ' Plugs directly into the 

VHF/One with no modification. " Noise blanker built-in. ' R IT and 

VXO for full frequency coverage. " S225.00 



Tufts Radio Electronics • 209 IVlystic Avenue • Medford iVlA 02155 • (617) 395-8280 



Tufts Radio Electronics •209 Mvstic Avenue • Medford MA 02155 • (617) 395-8280 



Thii N£rt MFJ Stiper Ai>t«nna Tuner 
. . . msiCliOT (rtETvlhi*^ Uam 160 ihru 
10 m^itr^: {jipalet, invsnud v<wz, 
randon> wirei, venicds, mobilb vrfiipS, 
b^am^ hflance liDf^j catti tin^i, U[> to 
200 Vltm RF OUTPUT, aurilin bjilun. 



Wlh Ihe MEW MFJ Stiper Antenna Tuner 

yoii can run your full transceiver power 
output - up to 200 watts RF power output 
- and match your transmitter to any 
(eedline fram 160 thru tO Meters whether 
you have coax cable, balance line, or 
random wire. 

Yon can lune out the SWR on your 
dipDie, inverted vee, random wire, vertical, 
mobile w'hip, twam, quait, or whatever you 
have. 

Vbu can even sperate alt bands with just 
one existing antenna. No need to put up 
separate antennas for each band. 

Increaie the utalile bandinridU) ot your 
mc&ile whip t>y tuning out the SWR from 
IntUe your car. Worlts great with all soliit 
Quality live way binding posts are used for 
the balance lifse inputs (2), random wire 





THE HAM-KEY 

NOW 5 MODELS 



Dealer Programs 
NOW Available 



input (t(. and ground (1 ). 

state r^QS (like the Atlas) and with all tube 

type figs. 

H travels wal, too. Its ultra compact size 
6x2x6 inches tits easily in a small comer 
of your suitcase. 

The secret of this tiny, poiwerful tuner is 
a wide range 12 position variable inductor 
made from iwo stacked toroid cores and 
high quality capacitors manufactured 
especally lor MFJ, Fw balanceil lines a 1 .A 
(unbalanced to balanced) b<ilun is built-in. 
Made in U.S.A. by fdFJ Enterprises. 

This beaultfui I'iltte tuner is housed in a 
deluxe eggshell while Ten-Tec enclosure 
with walnut grain sides. 

SO-239 ctan conneclora are provided 
for transmitter moot and coax ted antennaS- 
Price: SB9.95 



This Digital Alarm Clock is aiso an ID Timer. 
Assembled, too! 



Fhi ttr^ .63 inci) itgfli provide precise time to 
!h« minute. Secorifa afvea' ai th« tcucn iit the \Oi6oie 

twtlDfl. 

Pnitlng Ibt iUtfozf aiut fast set tiutton! reset ami 
riold the secwws lo zere tor precise setting to WWV 
until tlie i^st set ttutloo i& i«l6as^- 

The iBlurttt AM ar PM LEO indlcalQi^ blirk at s 1 
Hr rate it ttie pow^r goes oil mamBntaiily, For longer 
pDwer outs it resets \o T7M AM ,Mid tlie AM LEO 
Blinks. 

SffMng llif ttnie ini Aim is simple and tasi wilti 
'.tie fast atid slpu set QuttDjis £vcn !tie XYL will tind 
It tun 

Tin V*C, ea Hi S Ha « 3 3i'4 J 3 3ia .PCtBS Q-! 
■,ea' wsi'inty 
Prfco: SI 9.95 



Vfd tui |t( H D tam mty 9 mioules [u^ to one 
tiour] Simpty set ttw alaim lime to ttie tiegjnning ol 
yoai OSO Ttieii las tlw lOf&tte bErtlon, 

Yh cin itio Ed Uh Mitrm To ttie exa ' i lute to 
remiiKl >ou ot a SKEO or sitnply to waXe y.^ -jp in The 
ntntning imtofti^licaJly ewfiy 24 tioitis t n>:e:t lo 
i6itttnixr eveiv tiichl to 5*\ ttie ai^niil- 



NEW 

MODEL HK-i 

ELECTRONIC KEYER 

$69.95 



* lamblccircuif for squeeze keying. 
■ Self completing dots Bedashes. 

« Dot memory. 

« Battery operated with provisions for 
external power 

* Buitt-instde-tone monitor. 

* Speed. Volume, tone & weight confrafs. 

* Grid-block or direct keying. 

* Use with externa I paddle such as HK-1. 



Mode! HK-1 $29.95 

• DuaHevej^ sqireeze paddle. 

• Use with HK-5 or any electronic keyer. 
« Hedvy base with norvslip rubber feet. 

• Paddles reversible for wide or dose f lr>ger spacing. 






Model HK-3 $16.95 

• Deluxe straight key. 

• Heavy base< no need to attach to desk. 

• Velvet smooth action. 




Mode! HK-2 $19.95 

• SameasHKUessbase 
lor those who wish to 
iTicorporato in their 
own Keyer, 



#^ 



Model HK-4 $44.95 

• Combinalion Ofi HK-1 & 
HK-3 on samebase. 



400% MORE RF POWER 
PLUGS BETWEEN YOUR MICROPHONE AND TRANSMITTER 




LSP-520BX. 33 fiO dynamic range IC leg amp ^.-Cl 3 
ailive iiHas give cIpsi audio RF ptoieciftd. 9 V 
baHery 3 ;m!1(Juc1g^, Vi" pfrorre jacks 'r,r trp^' 
and ourpul. 2-3i16 K 3-Nd X 4 inches 



LSP-520BX 11. Same as LSF-520BX &l: " a 
tssL,'i!uT Z-i;3 X 3-5^a X : J '& inc-i Ten-Te;: 
ec^'tjeur^ wilh uncomirtillf-J ■; D' MjC laC*. 
;:'j'aLjl catjie fO!afv lunciiOf. sw.iz'r 



SUPER- LOG ARtTHMIC 
SPEECH PROCESSOR 

Up to 400% More RF Power is yours with this plug-in 
unit. Simply plug the MFJ Super Logarithfmic Speech 
Processor between your jroicrophone and transmitter and 
your voice is suddenly transformed from a whisper to a 
Dynamic Output, 

Your signal is full of punch with power to slice through 
QRM and you go from barely readable to "soiid copy OM." 





## 



mjF NEW.. 



CWF-2BX Super CW Filter 

By lAr (be teader. Oviir 50(X> in usd. Rtaat ^harp 
tnlKtivily. SO Hz bandwidth, exIr&mBly ^(eep 
skrrls. No ni>ging. PlugK between r«c«iveT and 
ptionss r>r connect b«twe«n audio MM90 tor 
spoaiier opefatJon. 

■ S'3)ec:5Dte BVV; 30, nO. ^80 Hz • 60 ciJ cJown 
one ociave from cenier treQ, o' 750 m for 8C Hz 
EW ■ Redjcea r^oist 15 dB • 9 V b3i[Bry 

■ 3-3/16 X 3-1 M X 4 ir 



CMOS-a043 Electronic Keyer 

StSit of ttie art design usea CURTIS 3043 
Keyer-on-a-chip. 

* Bu:'t -1 Ke> « Dol mafniH-,- * ]3TVbiC cpe'a- 
i.c." A.'T pJ!e'"*al scuccjp hpy • S to S-O 

ijrre. '.one. weight comr^'J 4 U Ita rs.atife sclir) 

stale key.n-g -3G0 vCilE- rfi3)i * i posf[ion 
SwMCh for TUNE. OFF ON SIDETQNE QfF 

• uses A peniiphi ceils • 2-3!i6 x 3-im x j 
I r Che 5 



MFJ-16010 ftntenna Tutier 

Now you tan operate aW band — IBQ itim 10 
Meters — wjiti a single random wire and luft youf 
full transceiver power outoul — up lo 200 WJtts 
Rt^ power OUIPUT. 

* STia ien.3Ligh '.3 c^s-y in yoi;: "13 p:ickei, 
2-3 'IS s 3-'.'-i X A inches • W8!che5 .d* and 
t'ltgt' imp^Gvirces by iniet'crunf^ing itd^' and 
aulput • 50-239 coaxial cormector^ • Uniq;je 
Wide range, high pertorrnance. ^^ p<?5Hion lapped 
inducior. Uses [wo slacked loroid corpi 




NEW 



CPO-555 Code Osciilatof 

For the Newcompi to learn iho Mars^ code. 
For itie Old Timp/ lo polisTr his l>^l. 
For ihe Code Iry&lrrjctor lo leach his c'jsms. 
• Sere z->?.'> - cS" cote utiih ;;.fr:t cl vclur-e ^:;f 
t asfe-Gon- us* ■ s^\ caniaiiBC S:jiS^>;e- jc?- 
urru, 'fine conirO'" ^Irjr^i'ium cattin'^l • 9 V 
t>it'.er> « Topqual-ly U.S. CCnS'ruClinr, * Uses 
5S5 IC timer « 2-.1M6 X 3 IM i- =i inctncs 




95 



SBF-26X SSB Filter 
brnnuillcallv improves reMtability- 
» Opitmzes /QUI audio 10 reduce s.deb^md 
spfaner, -einov& low and mgh pilcl^ed OHM. his3, 
static Crasfies, DackgroLi^d no^se, 60 apd 150 Hz 
hum « Hedsjces laiiCiLie dunrg contest, OX, and 
ragchewing * Plugs beiween ptioties und re- 
ceiver or conr^ect tje+wa^n audio stage lor speaker 
ofjtraiion * Seledable bandwidth EC active 
audio filter ■ Uses ^ wolt baltery • 2-Sn6 x 
3-1 f-l x 4 inches 



MFJ-200BX Frequency Standard 



Piovrdes strong, ptecise markers ewer/ 100. 50. or 
25 KHj well Jnto V>lF iS<j''Cn. 

• Exclusive CLrcu!lr> ^uyyresses al' jnwanwd 
marke's • tvisJkers sre giil&d for positive tdenVi- 
fjcaiion CMOS IC's- wrilh trarisistor output • No 
direci (;onr>eciior^ neces5.arv ■ U&es 9 volt 
ballerv * AdjuslabSe trimmer for zero beating lo 
WWV • Swilcfi selects lOO. 50, 25 KHz or Of'F 
« 2-3/1& t 3 ua X -1 inches 



MFJ-toaoBX Receiver Preselector 



Clearly copy weak unreadable signals, [increa^as 
signal 3 ID S "S" unitsi. 

« Mote jvart 23 dB lOv/ ncise gam • Sepiraie 
ina'jt and Output turimg controls give maximum 
gsm ana RF .selecfi/iiy to sipni'icantly reject 
□ut-ol-band si^i^als and reduce irriaqe responses 
* Djal gale KlOS FET for Sow noiss, strong signal 
hanijling ab>lLl>e& ■ Coimplelely stable • Op- 
timized lor 10 thru 30 MH? ■ 9 V battery 
■ 2-1 le X 3-5'B X 5-9n6 mches 




MFJ-10T QRP Transmiller 

Wori^ the world with 5 watis Qii 40 Meter CW. 

• Mo -unrnT; ■ ,"/3(r^e& S'O ot:- -vd^l « C'ear 
Output u^.tn \QM harrnor^c corne-r ■ Pow^' 
amplilier 'ransHStor cfoleciec agM ist DuiTiOUt 

• Switcti selects 3 crystals or VFO nnpul • 12 

VDC • 2-3*16 > S'1 /I X o inches 

MFJ-40V, Companion VFO S?7.95 

MFJ-12DC, IC Renulaled Power Supply, 

1 amp. 12 VOC 527 SS 



Tufts Radio Electronics • 209 Mystic Avenue • Medford MA 02155 • (617) 395-8280 



082S-S6S (^L9) • SSLZO VIAl PJO^P^IAI • anuaAy oiisAj/y ©02 • so|uoj^oe|3 ojpEy s^^ni 



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dO Sanill 03103138 Sidfll 




0aZ8-S6£ (Z.L9) • SS120 VIA! PJOiP^IAI • snusAV ofisAiAl 602 • saiuonoaig oipey sjjini 



Nen^ Products 



from page 22 

meterl, and a larrinatscf vswr chart. 
The price for this equipment is S298- 
The test set is cushion-fit assembled 
in a durable, MlL-spec polvethyiena 
case with space for seven piug-in 
elements, which determine power snd 
frequency ranges. The carrying case 
and vswr chart are complimeniary 
with the kit. 

A customized luggage-style transit 
case has also been announced. Model 
4300-070 has space for a Model 43 
wattmeter, 15 plug-in elements, and 
additional accessories. Cushion inserts 
for other configurations can be 
designed for quantity requirements. 

Price: 4300 064 tssi set S298, 
pljg-in elements S36-75. Delivary: 4 
vjeeks ARO from Bird Elecironic Cor- 
poration, 30303 Aurora Road, Cleve- 
lami (Solon) OH 44139. 



GARY MODEL 120 
DMM CALIBRATOR 
ilVIPRESSIONS 
"What good is my new, super ac- 
curate digital multimeter if I can't 
calibrate it?" you might ask, after 
purchasing such a device. Not a bad 
question, and considering the popu- 
larity of digital meters these days, it is 



a question that should be addressed. 

DMMs are capable of extreme ac- 
curacy, which is of not much use 
when no method of initially cali 
brating the device is available. The 
Gary McClellan Company, a manu 
focturer of DMiVl kits, has provided 
the solution to the problem with their 
IWodel 120 DMIVi calibrator. 

You may recall that last month I 
reviewed the Gary McClellan 103 
DMIW kit, the S29 special. I needed to 
calibrate that device, as well as my 
trusty analog meter. McClellan re- 
sponded by providing the 120 cali- 
brator to review. 

The 120 calibrator uses an internal 
iC to provide voltage references of .1 
volt at .2%, 1.0 volt at .2%, and 10.0 
volts at .1%. Additionaliy, resistance 
references from 100 Ohms to 1 
megohm are provided with similar 
accuracy. The calibrator is housed in a 
small plastic case with "banana" jacks 
for output connectors. A push-button 
enables the device when required, thus 
saving the internal 18-vo.t 
battery, consisting of two 9-vo!t tran- 
sistor batteries. 

As expected, operating the 120 
caiibrator is as easy as pushing the 
enable button. The meter or DMM to 
be calibrated is set to the appropriate 
range and adjusted while firing the 
calibrator. For the first time, I was 



really confident of the accuracy of my 
meter, The calibrator is so compact 
and easy to use that it can be used at a 
moment's notice — I keep mine 
directly behind my old VTVM for 
periodic checks. The decade voltage 
references also allow meters to be 
checked for linearity. 

All things considered, the McClellan 
120 DMM calibrator is a useful piece 
of test gear — usable by anyone with a 
DMM or VTVM, which incfudes just 
about everyone! 

The Model 120 calibrator is priced 
at S34.9 5 factory built. Gary 
McClellan and Company, Box 2085, 
1001 W. Imperial Hinay, La Habra 
CA 30631. 

John Molnar WA3ETD 
Executive Editor 



THE SNOOP LOOP 
Sencore, manufacturers of high 
quality test equipment, has made 
available a closed loop for signal pick- 
up and frequency measurements, 
without connecting to the circuit. The 
Snoop Loop is simple in construction, 
as it connects directly to a 50 Ohm 
input cable for direct apprication to 
the new Sencore FC45 frequency 
counter or the PF147 UHF prescaler. 
The Snoop Loop works equally wel 
on other 50 Ohm input frequency 
counters, as it enables the user to 
"hold back" from any of the high 
power sources, without actually con-' 
necting to the source, as it protects 



the frequency counter and the oper- 
ator. Then, too, the PL207 Snoop 
Loop can be used to "snoop bacit" all 
along the signa; path all the I'/ay back 
to iow level circuits and be placed 
directly over osciTator coils, for ex- 
ample, without upsetting the oper- 
ating frequency of the oscillator. The 
Snoop Loop model PL207, at S9.95, 
can be purchased from any Sencore 
distributor, or directly from the Sen- 
core service tfepartment in Sioux 
Falls. Sencore, 3200 Sencore Drive, 
Sioux Falls SO 57107, (605) 
339-0 WO. 



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IN KIT FORIM 

Now, for the first time, the proven 
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The Bird Dog was designed for long 
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motorists sho'.v the Bird Dog to detect 
moving police radar as far away as 2:4 
TO 3 miles. A unit with this type of 
sensitivity alerts the motorist of police 
radar long before the police radar has 
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detectors now on the market. 

The Bird Dog is usually located on 

Continued on page 189 



FREQUEW 
IN STOCK 



CIES 



146 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
G 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 
6 



.01T 

,61 R 

.04T 

.64R 

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.77SR 

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2 ai@t!©!? (m^ 



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ISR 
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90T 
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GTi^ 




fa lllh©§© 5?acoli®^ 



CleccHT-146 

Drake TR-22 

Drake TR-33 rec only 

Drake TR-72 

Genave 

Heathkit HW-202] rec only 

Heathkit HW-202 
Jcom/VHf' Eng 
Ken/Wilson 
Lafavette HA-146 
Midland 13-505 
Regent;y HR-2, A 



Regency HR-2 12 
Regency HR-2B 
Regency HR-312 
Regency HR-2MS 
S B E 
Sonar' 1802-3-4, 3601 



Standard 146/826 
Standard Horizon 
Swan FM 2X 
Tempo FMH 
Trio/Kenwood TR22O0 
Trio/Kenwood TR7200 



Note If you do not know type of radio, or if you/ radio is not listed, give fundamental 
trequency. formula and loadir^ capacitance. 
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Store Hours 
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168 



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Gai:y.MCCIcllanc<52 

P.O. Box 2085 
1001 W. Imperial Hiway 

LaHabra CA 90631 gio 



HATRY 

electronics 

500 Ledyard St., Hartford CT 06114 
203-527-1881 



(1 block east of Wethersfield Ave. off Airport Rd. 
Rte. 6) 

See Ward W1WRQ - John W1JJR 

or 

Dave WA1HFE 



HEADQUARTERS for 2IVI FM 
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AIVIATEUR GEAR 
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Mosley, Hy-Gain, CushCraft. 



(Canadian Amateurs Send U.S. Funds Only) 

F.O.B. Hartford 

Please include postage 




169 



C. Charles Roukas '. 
9 Tuxedo Pk 
Rome NY 13440 



'2DNY 



- - this one's for the Wilson 



Remote Speaker Mike for Your HT 



I received my Wilson 
1402SM HT a few weeks 
ago and i m mediately 
started having a ball mobiling, 
both on fool and in the car. 
In using it while in the car, I 
connected it to the rooftop 
5/8 wave antenna. It was a bit 
awkward to use however, 
holding it up to my face and 
using it "a la a great big 
microphone." The micro- 
phone, located close to the 
bottom on the Wilson instead 




Fig. 1 . Using mike as speaker. 

of the customary position 
about 3/4 of the way up, 
didn't help any. In using it 
while I was walking, I found 
it embarrassing seeing people 
driving by and turning to 
stare as I either held it to my 
ear in order to hear 
adequately, or positioning it 
next to my mouth for trans- 
mitting. I'm no youngster so i 
can't qualify as a kid playing 
Dick Tracy. I decided that a 
remote speaker/microphone 
was an absolute must. A 
quick check with the ads re- 
vealed that I'd have had to 
come up with $24.00 for a 
new one. It might as well 
have been $240.00 as far as 
my pocketbook was con- 
cerned. That left me no 
choice but to try to home 
brew one. With my huge juntc 



box I didn't anticipate any 
parts problem. 1 live alone in 
a big house trailer. My friends 
say that I live in a huge junk 
box. My junk box se.rved me 
well, as I had all of the 
necessary "junk." In my local 
area, you can duplicate my 
unit for about $1 .50 if you 
have an old mike to start 
with. We have a fantastic elec- 
tronics surplus outlet here for 
the necessary "junk." It is 
most unfortunate that he 
does not handle mail orders. 
At first I tried a dynamic 
microphone itself as both a 
speaker and as a microphone. 
See r ig. 1 for details. 
Actually, the element was a 
Shure Brothers controlled- 
magnetic transducer. It 
worked, but the "speaker" 
output was quite low. The 
output compared to a 
transistor radio earpiece. I 
next tried various true 
dynamic microphone 
elements of different shapes 
and sizes. I found one that 
had usable output, at least 
while in the trailer, but left 
much to be desired as a 
microphone. It made me 
sound as if I was talking with 
my head in a barrel. I added a 
high pass filter between the 
element and the speech 
amplifier input, to 
pre-emphasize the highs. See 




Fig, 2. Using mil^e with filter. 



Fig. 2. The tone quality 
improved significantly, but 
the output suffered to the 
point of requiring my yelling 
into the mike. I changed the 
filter configuration to that as 
shown in Fig. 3, and it 
sounded normal. I did, 
however, vary the resistance 
value so that the deviation 
level was normal as well. This 
worked out reasonably well 
except that, needless to say, 
in a noisy environment, the 
''speaker" output was 
somewhat low and the unit 
had to be held up to one'sear 
as with an earphone. Another 
drawback was that the 
internal speaker would still 
"squawk," and consequently 
1 could not operate in quiet 
environments, i.e., restau_- 
rants, libraries, hospitals, etc. 
Operating mobile on foot 
didn't work out too well 
either. I had the unit snapped 
to my belt and under my'" 
jacket, as ft was cold out 
This necessitated using the 
"mike" as an earphone 
continuously as I could not 
hear the internal speaker at 
all. Boy, does your arm ever 
get tired after awhile. Using it 
in the car wasn't acceptable 
either. The audio {from the 
internal speaker) was not 
loud enough to overcome the 
din of a noisy truck passing 
by and I couldn't continually 
hold the "mike" to my ear 
and still perform prerequisite 
driving functions. Oh well, 
back to the drafting board. 

! then attempted using a 
small {V/i") speaker both as a 
mike and speaker — the in- 
verse of what I had tried 
previously. This worked out 
very satisfactorily as a 



speaker but not as a mike. 
Once again it sounded as if 1 
was talking while I had my 
head in a barrel. The circuit 
was the same as that of Fig. 
T, except that the element 
was a speaker. Since the 
deviation was low as well, ! 
added a micro-miniature 
transistor output transformer 
to the mike input circuit for 
proper impedance matching. 
See Fig. 4. This increased the 
output to the point of 
overdeviating. The quality 
remained bassy. I added a 
high pass filter as with the 
dynamic element and got it 
sounding "hi-fi." The final 
circuit is shown In Fig. S. 

I can now drape the 
"mike" over my shoulder, 
either while using it in the car 
or while walking with it and 
it works fine. The audio level 
is more than adequate to 







/77 



qrr 



Fig. 3. A better filter 
for transmitting . . . 

override extaneous noises. 
The audio level control is 
now set so low that the 
raucous racket previously 
emanating from the interna! 
speaker is now the equivalent 
of a stout whisper. I used a 
standard communication 
hand mike case for my unit. I 
held the speaker in p!ace 
using silicone rubber (bathtub 
caulk), I replaced the push to 



170 




Fig. 4. This one hears well . . . 

talk switch (it was only dpst) 
with a miniature push-button 
panel mount switch. My 
speaker/microphone works 



like a charm, and I've had 
nothing but compliments 
regarding how nice it sounds. 

If you're wondering why I 
didn't try a separate 
miniature microphone^ the 
answer is simply that my junk 
box did not produce one. I'm 
glad now that it did not. I did 
entertain the thought of a 
separate standard size 
microphone but could not 
squeeze one into the mike 
case along with the speaker. 

This means of 



accentuating the highs 
(pre-emphasis) to make the 
microphone sound "human" 
applies to any microphone 
element. I even tried it with a 
carbon mike and now its 
quality can't be told from a 
communications type crystal, 
ceramic or dynamic 
microphone. Try it with a 
cheap (home tape recorder 
type) dynamic and make it 
sound "hi-fi." The values have 
to be altered to satisfy the 
characteristics of your speech 



/77 




Fig. 5. Eur elf a! 
The fir>!shed unit. 

amplifier and to compensate 
for the particular microphone 
element that you're using. ■ 



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.Zip- 



171 



Bob Tsshjian WA60MH 
24100 Hamlin Street 
Cunoga Park CA 91307 



Split Your IC-22S 

" adding splinter frequencies 



The IC-22S has brought 
the versatility of a 
synthesized 2 meter trans- 
ceiver finally within the reach 
of those without unlimited 
funding, apparently by avoid- 
ing thumbwheel switches, 
digital displays, and the cir- 
cuitry that these devices 
require. However, it has a 
limitation shared by most of 
the new synthesized rigs — it 
is restricted to operating on a 
500 kHz split. \n most locali- 
ties this is no problem, but 
here in Los Angeles one of 
the most popular repeaters 
uses an odd split, receiving on 
147.435 MHz and trans- 



mitting on 146.40 MHz. 
Numerous other communities 
also have this problem. 

The IC-22S uses a diode 
matrix to program its fre- 
quency synthesizer for the 
lower of the two frequencies 
to be used. The selector 
switch selects a particular set 
of diodes. The output of the 
diode matrix goes to a digital 
adder circuit which adds 600 
kHz (a binary 101000, where 
the least significant bit repre- 
sents 1 5 kHz) when the 
higher frequency is called for. 
To modify this circuit would 
be a tedious job and, in all 



likelihood, would make it 
difficult to restore the circuit 
to its original state should 
in-warranty service be 
required. What must be done, 
then, is to use a different set 
of diodes for the second 
frequency. 

When I first studied the. 
circuit, 1 was disappointed to 
see that the voltage levels 
used were and 9 volts, 
which eliminated the use of 
TTL devices. 1 was just about 
to settle for using a relay, but 
the thought of using a relay' 
in a solid state device left me 
cold because of the threat of 




IC-22S modification. Note pigtalted connection to existing wire to switch in center and new iC 
sockiet witfi sleeve removed at left. 



damage caused by transients 
from the coil. Nine volt relays 
aren't too easy to find, either. 
Then I noticed that the logic 
following the diode matrix 
was all CMOS, which operates 
on a supply voltage of any- 
where from 3 to 1 5 volts. My 
problems were over. 

In this circuit (Fig. 1 ), a 
CD4001 CMOS quad NOR 
gate chip provides all the 
gating necessary. The two 
inputs are the line from the 
selector switch and the "dp" 
line. The "dp," or duplex 
line, enables the adder circuit 
and here is used to enable the 
second set of diodes and dis- 
able the first. Both sets are 
disabled when the channel 
selector switch is not in the 
special position. The two 
outputs go to what I call the 
"normal" and the "abnor- 
mal" diodes. The normal 
diodes select the frequency to 
be used when the "dp" line is 
false (0 V), and the abnormal 
diodes select the frequency to 
be used when the "dp" line is 
true (9 V). In my particular 
case, because it is desirable to 
be able to -r^eceive on the 
repeater input for T-hunts or 
when there is interference on 
the output, 1 use the duplex 
A position. This position 
enables the adder logic ("dp" 
line true) in the receive mode. 
Therefore the -diodes for 
receive (146.40 here) must be 
programmed for 600 kHz 
lower, or 145.80. Although 
this frequency is supposedly 
out of the range of the 
synthesizer, it doesn't really 
matter because the adder cir- 
cuit intervenes before the 
145.80 information ever 
reaches the synthesizer. There 
is plenty of range in the diode 
arrangement to program 600 
kHz below even 146.01 MHz. 
Switching the function switch 
to the simplex position allows 
both receive and transmit on 
the normal frequency. 

Construction is fairly 
simple. I wired everything on 
the back of a 14 pin IC 
socket, which fits very nicely 
between the volume control 
and the synthesizer board. 1 
didn't fasten the IC socket to 
anything but just let it float 



on its wires. This allows 
removing the diode board and 
new circuitry as one unit for 
programming. To insulate the 
IC socket, I slipped over it a 
paper tube made from pack- 
age sealing tape — that's the 
stuff you have to lick. It 
tasted dreadful but did the 
job. The normal diodes 
occupy the position corre- 
sponding to the switch posi- 
tion to be used. At the end of 
the diode board, adjacent to 
diode position 22, is an 
unused position just made to 



order for the abnormal 
diodes. To get to the lead 
coming from the selector 
switch, unsolder it from the 
diode board and replace it 
with the "normal" lead. The 
positions of the 9 volt and 
"dp" lines are marked on the 
board. The only thing missing 
on the diode board is a 
ground, and this is available 
on the meter. 

The only problem en- 
countered was rf occasionally 
getting into the new circuitry 
and causing loss of lock. 



CHAMWEL 
SELECrO^^ 



f\N Pfl- 9V 

PIN 7 - GROUND 



]■" 



"mormjiI." 

oion£S 



-"AehORWAi: 
DIODES 



Fig. /. 
some bypassing radio. 



Presumably 
would have prevented this, 
but it was found that there 
was no trouble whenever the 
antenna was not actually 
mounted directly on the 



It's great that repeater 
splits are as standardized as 
they are, but for those which 
aren't, this is an easy, inex- 
pensive solution. ■ 



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Fig. I. 






r/c?. 2. 



Remote Monitor 
for Your Scanner 



--complete with lights 



This article covers a cir- 
cuit modification made 
to a Regency model 
TIVIR-8H/LiVl scanner monitor 
whicli replaces the channel 
indicator bulbs with light 
emitting diodes and includes 
the construction of a remote 
active channel indicator. 
Material cost for this project 
is quite reasonable and, 
depending upon the con- 
dition of the shack junk box, 
should amount to less than 
$5.00. Light emitting diodes 
are type MV5026, red, priced 



at 5/$1.00 just about every- 
where. Other than the LEDs, 
the only parts needed are 
nine 390 Ohm 2 Watt resis- 
tors and a junk box speaker. 
The technique described 
should work equally v/ell 
with other brands of scanners 
as the ci-rcuitry is simple and 
straightforward. 

The scanner in question 
is (rather permanently) in- 
stalled in the basement work- 
shop shared by me and my 
retired fireman father. Most 
of the fireman's workshop 



time is spent in pursuit of his 
hobby at a power jigsaw. 
Obviously, when the scanner 
locks on a channel, far too 
much energy must be 
expended to turn around and 
look fifteen feet to see which 
channel is active. To 
eliminate this problem, an 
assembly containing a remote 
speaker and eight light 
emitting diode indicators was 
constructed and mounted on 
the wall in front of the saw. 
A labeimaker was used to 
affix the channel assignments 
adjacent to the proper LED 
indicators. 

The remote indicators are - 
wired in parallel with the 
indicators in the receiver. Fig. 
1 shows the circuit diagram 
of the existing control cir- 
cuitry for one channel. 

IC301 is a power NANp 
gate which when activated by ' 
the scan decode circuitry 
functions such that its appro- 
priate output (such as pin 4 
in the figure) becomes -a" ■ 
current sink effectively 
grounding pin 4. As well as 
activating the channel crystal 
Y201, the programming cir- 
cuitry diode CR301 selects 
the appropriate high or low 
band mixer and at the same 
time must sink 120 mA just 
to light the channel indicator 
bulb. Not wishing to see if 
the additional 35 mA drawn 
by the remote LED in parallel 
with the No. 53 bulb would 
be the straw that broke the 
camel's back, it was decided 
to replace the bulbs with 
LEDs. 

It is claimed by some 
scanner-owning visitors that 
with the LED indicators on 
the receiver, the locked 
channel is easier to determine 
at a quick glance because of 



the more point source light 
characteristics of the device. 

To install the LEDs is as 
simple as replacing each light 
assembly. After removing the 
bulb assembly, it is necessary 
to use some method of 
supporting the diodes. This 
turned out to be mechani- 
cally simple though elec- 
trically redundant. As shown 
in Fig. 2, one end of a 390 
Ohm 2 Watt resistor was con- 
nected to the -^13 V B-t- line 
on the circuit board. 

The body of the resistor 
was positioned facing the 
opening in the front panel. 
The anode of the LED was 
then carefully soldered to the 
panel end of the resistor 
while the '"ca-thode was 
soldered to the appropriate 
contact on the channel lock- 
out switch (same point as the 
removed bulb). The LED was 
aligned in the panel opening 
and that's all there is to it. 

The remote installation is 
■quite simple. A cable or wire 
bundle or whatever you 
choose to call it is required, 
and contains a pair of wires 
for the remote speaker. These 
may Jbe connected directly to 
the remote speaker terminals 
on the rear of the receiver 
chassis. The cable which can 
be routed through an existing 
opening in the rear of the 
case must also contain an 
extension of the +13 V B+ 
line and a control wire for 
each channel indicator. These 
control wires are connected 
to the respective channel 
lockout switch previously 
described. Rather than be 
restricted by a hard- wired 
cable, I mounted a jack on 
the back of the chassis and a 
plug on the cable. (This 
would be up to individual 



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preference.) A circuit diagram 
of the remote unit is shown 
in Fig. 3. 

Construction of the 
remote unit can take just 
about any form which is con- 
sistent with your abilities as a 
carpenter, cabinetmaker, 
sheetmetal worker or tin 
knocker. IVIine is quite simple, 
being made out of some kind 
of fibrous pressboard 
material which makes friction 
fitting of the LEDs possible 
as a method of securing. A 



Dymo-maker was used to feeling of being on final 



label the appropriate cities 
and towns beside each indica- 
tor using the "clever" scheme 
of red tape for fire depart- 
ments and blue tape for 
police departments. 

Having an installation such 



approach to an airport run- 
way at night. 

In conclusion, the intent 
here was to start the reader 
thinking of ideas for custom 
scanner installations. Putting 
the receiver on a good outside 



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Electronics 
Study Guide 



- remember when...? 



There's no doubt about 
it. Some of the most 
delightful observations about 
electronic communication 
have been scrawled on tablet 
paper by grade school 
youngsters. Having taught in 
public schools for nineteen 
yearSj I'm sure of it. Take 
these historical explanations^ 
for example. 

Question: "When was the 
radio invented?" Answer; 
"On page 24." 

"The radio was invented in 
the pre-me limes." 

"The Romans did not have 
radios. They used srnoke 
signals in both the A.C. and 
D.C. times." 

Kids have a knack for 
discarding everything but 
what they consider to be the 
most essential information. 
One boy brusquely wrapped 
up all of man's yearnings, 
struggles and triumphs in this 
eight word package: 
"Progress was from electricity 
to radios to now." 

Here's a remark as 
charming as childhood itself: 
"I was thinking the radio was 
invented before the telegraph. 
When I learned different, all 
the thoughts I was going to 
say went in a swallow down 
my throat." 

Another tiny historian 
concluded: "The Dark Ages 
lasted until the invention of 
electricity." 

Through the years, the 
grade schooler's fund of 
knowledge has proved to be a 
glittering gold mine of wit 



and unconscious wisdom, 
often unhampered by hard 
facts. Each new subject seems 
to be a fertile new field for 
ofTbase interpretation and 
lopsided logic. Digging into 
facts about Marconi produced 
such notable nuggets as these: 

"Marconi was born in 
1874, supposably on his 
birthday." 

"It took much hard work 
for Marconi to think out how 
to invent the radio. He had to 
keep thinking around the 
clock, twelve days a week." 

"In just a few short years 
he became a sensation over- 
night." 

"He expired in 1937 and 
later died from this." 

Last year a bright-eyed 
little radio enthusiast came 
up with this endorsement: 
"Every time I think how the 
radio gives us so much fun, I 
have joy feels all over." 

A skeptical classmate of 
hers absorbed all the statistics 
regarding the number of ham 
radio operators in America, 
but got his skepticism across 
in one crushing statement; 
"The total amount of ham 
operators in America today is 
more for saying than 
believing." 

It must run in the family. 
Two years later his younger 
sister reported: "The number 
of ham operators we have 
today is an adsurbly large fact 
of a number." 

The subject of hams has 
stumped many eager young 
scholars. Here are three more 



futile but imaginative explan- 
ations: 

"Ham operators look 
something like people." 

"They are one of the chief 
by-products of electricity." 

"The meaning of ihem has 
a very short memory in my 
mind." 

The elementaiy school 
youngster's mind seems. to be 
a vast storehouse of miscel- 
laneous misinformation — 
haif true, haif false and 
wholly delightfuL His fund of 
knowledge about electricity 
includes such fascinating 
items as these: 

"Electricity has been with 
us forever and maybe even 
longer." 

"Would the average person 
be able to keep up with the 
news if it was not for 
electricity? The chances are 
999 out of a hundred." 

"in electricity, opposites 
attract and vice versa." 

"If you see lightning, no 
you don't. You see electric- 
ity." 

"From now on, I will put 
both gladness and wonder in 
my same thought about elec- 
tricity." 

Here's one I've been trying 
to figure out for five years; 
"You should always cap- 
italize the word electricity 
unless it is not the first word 
in the sentence." 

This next little girl seemed 
to be giving it all she had 
when she wrote: "Correct my 
being wrung, but tell me true 
or false. Do negative charges 



go through electrons or 
through protons? I wrecked 
my brain trying to think 
which." 

But I'm afraid others are 
more nonchalant in their 
pursuit of knowledge: 
"Protons are bigger than 
eSeCtrons in case I ever want 
to know." 

Psychologists tell us that 
half learning a fact incor- 
rectly is often the first step to 
learning it right. So let's be 
philosophical as wc buzz 
through these fractured facts 
about electrons and protons: 

"100 electrons equal 1 
radio program." 

"When the switch is on, 
electrons are constantly 
bumping into each other 
inside the wire. There is really 
quite an overpopulation of 
electrons." 

"Once I saw in an educa- 
tional cartoon about how 
electrons move. Electrons are 
very interesting folks. All 
their ways are hurry ways." 

"Electrons carry the 
negative charge while protons 
take the affirmative." 

"Electrons, are the same as 
protons only just the 
opposite." 

"I think I admire the 
,.. electron more than anything 
else about electricity because 
it weighs only about one over 
2000th as much as- a proton 
but can still hold its own." 

Obviously, one of the 
fringe benefits of being an 
elementary school teacher is 
the possibility that the next 
paper I read will contain a 
wroiTg answer that is twice as 
witty or thought-provoking as 
the expected one. Sometimes 
they don't know and they 
know they don't know, but 
that doesn't keep their 
answers from being charming; 

"Ideas about how radios 
work have advanced to the 
point where they are no 
longer understandable." 

"Did i pass the test about 
how to get a ham radio 
operator's license and why 
not?" 

"I have found radios to be 
easier to listen to than to tell 
how they work." 

Take three small boys, mix 



176 



them up thoroughly with 
several pounds of strange 
facts, then shake them up 
with an examination and you 
have the perfect formula for 
instant confusion. Here's 
what ! mean: 

"The way vacuum tubes 
work, as I understand it, is 
not very well understood." 

"Many questions have 
been aroused in my mind 
about vacuum tubes. As a 
mattery fact, the main 
trouble v/ith vacuum tubes is 
that they give more questions 
than ansv/ers." 

"In electricity, positives 
are attracted by negatives for 
the reason of search me." 

Judging from the size of 
the handwriting, this next 
tyke was under the influence 
of John Hancock when he 
took time out to report (with 
the aid of a bright purple 
Crayola): "When they asked 
my brother if he would like 
to watch a ham operator, he 
rolled his eyes and flashed his 
teeth and said sure." 

Often a grownup can only 
envy the simplicity of a 
child's way of expression, as 
is the case of the lass who 
remarked: "When I learned 
we were going to see a movie 
about ham operators all over 
the world, I told my feet to 
quiet down but they felt too 
Saturday to listen." 

In their worid of uncer- 
tainty, once they know a fact 
for certain, they hang on to it 
tenaciously, e.g.: "Another 
name for the radio is radio- 
telephony, but ! think I will 
just stick with the first name 
and learn it good." 

Children, like mountain 
climbers, must always make 
sure that their grasp on a fact 
is firm, even though they 
want to leap far beyond. 
Otherwise, they may find 
themselves trapped on a 
mental ledge called a boner. 
There is usually at least an 
element of truth in the most 
absurd answer. Sometimes 
they aren't wrong at all. It's 
just the way they put it that's 
so funny: 

"Radio has a plural known 
as mass communication." 

"Water scientists have 



figured out how to change 
river currents into electric 
currents." 

"The best thing live vi^ires 
are good for is running away 
from." 

"Quite a bit of the world's 
supply of electricity goes into 
the making of ham radios." 

"Mafiy things about elec- 
tronic communication that 
were once thought to be 
science fiction now actually 
are." 

Members of the grade 
school set certainly have their 
own opinions, and few are 
hesitant to express them: 

"All the stuff inside a ham 
radio is so twisted and com- 
plicated it is really not good 
for anything but being the 
stuff inside a ham radio." 

"Electronics is the study 
of how to get electricity 
without lightning." 

Then I don't suppose I'll 
ever forget this remark by 
another boy; "L.ast month 1 
found out how a radio works 
by taking it apart. 1 both 
found out and got in 
trouble." 

And you can't argue with 
the young fellow who re- 
ported: "When currents at 
110 to 120 volts go through, 
them radios start making 
sounds. So would anybody." 

When members of the 
grade school set turn their 
attention to the subject of 
vacuum tubes, youngsterisms 
come as thick as chalk dust. 
Just what is a vacuum? Here 
are five answers, fresh from 
the minds of nine-year-olds: 

"Vacuums are made up 
mostly of nothings." 

"A vacuum is an empty 
place with nothing in it." 

"Vacuums are not 
anythings. We only mention 
them to let them knqw we 
know they're there." 

"There is no air in 
vacuums. That means there is 
nothing. Try to think of it. It 
is easier to think of anything 
than nothing." 

"A vacuum tube contains 
nothing. All of its parts are 
outside of itself." 

Another lad wrote of this 
frustrating experience: "1 
figured out how a vacuum 



tube works twice but I forgot 
it three times." 

One of his classmates 
reported: "When 1 learned 
how empty vacuum tubes are, 
I would have fainted if 1 
knew how." 

If you're at all hazy about 
other parts in a radio, hang 
on. These next thoughts will 
leave you only slightly worse 
off than before: 

"An electron tube can be 
heated two different ways. 
Either Fahrenheit or Centi- 
pede." 

"When you turn a radio 
on, the tubes get hot. The 
hotter anything gets, the 
faster the molecules in it 
move. Like if a person sits on 
something hot, his molecules 
tetl him to get up quick." 

"In finding out that radio 
tubes get hot, the fun is not 
in the fingers." 

"Transistors are what 
cause many radios to play. 
Transistors are a small but 
important occupation." 

"We now have radios that 
can run on either standard or 
daylight time." 

Ohe of my students last 
year had many tussles with 
his spelling book. When he 
finished writing one partic- 
ular sentence, " the battle- 
ground looked like this: 
"Termanuls do not agree with 
themselves spelingly and 
pruncingly." 

With apologies to Mr. 
Webster, 1 would like to 
present a pocket-size diction- 
ary of pint-size definitions, 
compiled from school 
children's reports. Should any 
of them prompt Webster to 
turn over in his grave, he 
would have to do so with a 
smile: 

"Axually, a choke coil is 
not as dangerous as its name 
sounds." 

"Electromagnets are what 
you get from mixing elec- 
tricity and magnets 
together." 

"Think of a volt. Then 
yippee, because now you 
have had the same thought as 
Voltaire, after who this 
thought was named." 

Another lad had the right 
information, but the wrong 



answer; "There are some 
things about electricity we 
are still not sure of. These 
things are called whats. " 

If the kids don't know ail 
the answers, they can always 
do what their parents once 
did — try to slide by on a 
guess or two: 

"A radio telescope is a 
thing you can hear programs 
by looking through it." 

"Current electricity is elec- 
tricity that is currently in 
use." 

Kids are so full of ques- 
tions, they can't possibly wait 
for someone to tell them all 
the answers. That's why they 
plufige recklessly ahead on 
their own, like so: 

"Sound travels better in 
water than in air because in 
water the molecules are much 
closer apart." 

"I have noticed that if a 
portable radio is turned in 
different directions, the 
station talks loudest behind 
its back." 

"Although air is hollow it 
is not just for looking 
through. It is also for having 
radio waves running, thro ugh 
it and trying to answer 
questions about." 

"Radio waves would not 
"be all that important to study 
if it were not for ears." 

"Someone in here said 
that FM has shorter waves 
-than shortwave radios. Is this 
so? 1 think it is because I 
think I was the one that said 
it." (If you can't believe 
yourself these days, who can 
you believe?) 

An obviously more 
confident young man 
proclaimed: "Much has been 
said about how radio waves 
travel. Radio waves are both 
bearable and talkable." 

Another moppet was going 
great, until the last word: "I 
believe the radio is one of the 
most important inventions of 
all time. Of course my father 
works at a radio station, so I 
may be a little pregnant." 

That'5 one young writer 
who would have done fine if 
she had just stopped while 
she was ahead (which is good 
advice for grownup writers, 
too).* 



177 



Low Cost Tone Decoder 

- for repeater control 



Chris Winter 'NSQVSZ 
2040 Glass Road NE 
Cedar Rapids I A 52402 



The usefulness of the Bell especially for remote control decoders is quite low now, 
touchtoneTM system of repeaters^ is well known. chiefly because of the 
for remote control, and The cost of touchtone Signetics 567 tone decoder 




Fig. 7. Decoder circuit. 



ONE-0F-SlXrE:":{N 



^ VS VALID SIGNAL 



178 




OUTP J- ^ 

' + 

m 

Fig, 2. Basic clocii circuit. 

IC. However, you still need 
eight of these ICs for a fuli 1 6 
button system, if you use the 
standard method as described 
in Signetics Databook,'^ 

A scanning decoder can 
get by with only two tone 
decoder ICs. It can become so 
complex, though, that any 
cost saving is wiped out. I 
decided that a scanning 
decoder would be simple 
enough to be worthwhile. My 
version is similar to the one 
described in reference 3. It 
uses a pair of 567s, a 555 
timer, 2 CMOS quad switch- 
es, and 6 TTL ICs. All of 
these ICs are readily available 
from suppliers who advertise 
in 73. The total cost of the 
ICs should be under 10 
dollars. In addition, the 
decoder uses a handful of 
resistors and capacitois. 

Circuit Operation 

Fig. 1 shows a schematic 
diagram of the decoder. The 
eight tones used in the Bell 
system aie divided into two 
groups. The low group tones 

- 697, 770, 852, and 941 Hz 

- are referred to as LI , L2, 
L3, and L4, HI, H2, H3,and 
H4 are the high group tones, 
respectively - 1209, 1336, 
1477, and 1633 Hz. 

U1 decodes tones in the 
low group. Its frequency of 
operation is determined by 
C4 and one of the resistors 
R3-R6. The resistors are 
connected in succession by 
U2, a CMOS quad switch. 
The state of U6, a dual flip- 
flop, is decoded by U7 into 
four control lines. One of the 
lines is always high, closing 
one of the individual switches 
in U2. The frequency of U3, 
the high group decoder, is 
switched the same way. 

With no tone present, U8 



is held reset while U6 is con- 
tinuously clocked. When a 
pair of tones appears, as soon 
as UT is switched to the 
proper frequency, U1-8 goes 
iow. U6 is held in its current 
state, and U8 is allowed to 
cloci<. Then when U3 has 
decoded the high tone of the 
pair, its output goes low. US 
stops clocking and the valid 
signal line goes high. This 
indicates that the detection 
process is complete. 

The flip-flop outputs are 
combined into a four-bit 
binary representation of the 
tone co-de. This four-bit word 
also goes to a 741 54, which 
gives a low on the selected 
one-of-sixteen output. When 
the valid signal line is low, 
U10 is disabled — all outputs 
high. 

Construction 

There are no special 
problems in constructing the 
unit. Layout is not critical, 
and the wiring is not extreme- 
ly complex, so a PC board is 
not essential. Follow the 
normal precautions in 
handling the CMOS ICs, and 
do not omit the eight pullup 
resistors (labeled RPU in Fig. 
1). They protect the CMOS 
gates if the 740Ss are 
removed for any reason. IC 
sockets make troubleshooting 
a lot easier, but are not 
necessary. 

Some Notes on Design 

The basic timer circuit 
(Fig. 2) is derived from 
reference 4. The values of R1 
and CI give a frequency in 
the neighborhood of 4 Hz. 
R2 is chosen for a duty cycle 
of 50%. 

Fig. 3 shows some changes 
to the clock circuit, which 
make troubleshooting and 
alignment a lot less of a 
hassle. First, in order to set 
the frequency control resis- 
tors, it's best to defeat the 
cycling action and leave the 
proper CMOS switch 
permanently on. This is the 
purpose of ST It converts the 
555 from astable to mono- 
stable operation. Then, each 
time S2 is pressed, the 555 




Fig. 3. Modified clock circuit. 



produces a single pulse, 
and the state of the flip-flop 
advances by 1. To complete 
this revision, add a switch to 
ground pin 8 of UI. Some 
LED indicators driven from 
the four output lines are also 
handy. S3 simply lets the 
timer run fast enough so that 
the waveforms are easily 
viewed on a scope. 

If, unlike me, you don't 
like to add a lot of extra 
hardware just to ease setup, 
you can gel the same results 
with a couple of jumpers. The 
method is explained in the 
section on alignment. 

The eight pullup resistors 
can be any convenient value 
between 10 kiiohms and 1 
megohm. 

I used multi-turn pots to 
set tite frequencies of UI an3 " 
U3. Assuming C4 and C7 are 
exactly 0.22 and 0.1 tiF, you 
can calculate the resistance 
values from an equation in . 
reference 4. These values are 
shown in Table 1. 1 used 5 
kilohm pots in series with 
fixed 10% resistors. If you 
choose to set the frequencies 
with combinations of fixed 
resistors (more work but less 
strain on the budget). Table 1 
gives you starting points. 
Note that the values given 
don't take into account the 
series resistance of the CMOS 
switches. There are two types 
of switches you can use: The 
CD4016 costs less, but I 
recommend the CD4066 
because of its lower "on" 
resistance. You might also 
want to use more accurate 
capacitors for C4 and C7. 

In a standard decoder as 
shown in reference 4, the ICs 
will lock up very quickly. 
Lockup times less than 0.1 



second arc easily achieved. 
With a scanning decoder, 
however, yoti cannot count 
on decoding a pair of tones in 
[ess than 8 clock periods. It 
takes this long for both 
count-ers to cycle tiirough 
their four possible states. 
Each clock period must be 
long enough (or the vco to 
settle down, then lock onto 
the tone. Because of this, 
there is little need to 
optimize the lockup time, 
and the design is simpler. You 
only need to be sure that the 
detection bands for the 
various tones do not overlap. 
Bandwidth is reduced by 
increasing the' '-values of C2 
and C5, and C3 and C6. I 
found that the values shown 
in Fig. 1 gave a narrow 
■enough bandwidth. You may 
find that the high group 
bands overlap, especially H3 
and H4- If so, chafige resistor 
.values to move the bands 
apart. A high input level will 
increase bandwidth. Keep it 
as low as possible. 

Alignment 

A good audio generator — 
one with an output level 
control and an accurate 
frequency dial — is needed to 
align the decoder. You'll find 
that a scope and a frequency 
counter will be very useful, 

I'm going to assume that 
you've built the circuit on 
"anyboard" without using IC 
sockets or any of the frills 
described in the section on 
design notes. I'll also assume 
that you used fixed resistors 
for R3-R10. If you use pots, 
the procedure is almost the 
same. 

After checking for wiring 
errors, apply power and 



179 




ALOIO TO 
LOV/ GROUP 

DECODER 



JILDIO TO 
HIGH GRDl/P 
DECODER 



Fig. 4. Block diagram of input conditioning sclieme. 



measure the current. The 
decoder should draw about 
250 nriA. Be sure that Ull is 
producing a square wave at 
about 4 Hz. Then check that 
U6 is clocking normally and 
that pins 13, 5, 6, and 12 of 
U2 go high in succession. 
Now connect a jumper to 
Ul-S, and touch the other 
end to ground. This will stop 
U6, leaving one switch of U2 
closed. The trick is to get 
U2-1 3 high, closing the 
switch for the LI resistor. 
This will take a few tries. 

Once you have U2-13 
high, leave Ul-8 grounded 
and connect a decade box 
from Ulo to U2-1. Set it to 
the value tgiiven in Table 1 for 
the LI resistor. Connect an 
audio generator to the tone 
input. Set the frequency to 
700 Hz and the level to 0.2 V 
rms. Remove the jumper. 
Ul-S should remain low. If it 
does not, adjust the decade 
box as necessary until it goes 



low. Remember to wait 1 
second (four clock periods) 
between resistance changes. 
To fine tune the value, 
approach it from above and 
below and note the values 
where Ul-8 just goes low. Set 
the decade box halfway 
between them. Now lower 
the audio level to about 50 
mV rms. It's best to use the 
lowest level that will activate 
the decoder. Repeat the fine 
tuning process. This gives you 
the final value for R3. Select 
R4, R5, and R6 the same 
way, connecting the decade 
box in series with the proper 
switch each time. Now 
ground Ul-8 permanently 
Vi'ith the jumper. U4 should 
start switching. Use another 
jumper from U3-8 to ground 
to set the proper switch of 
U4 on, and select R7-R10. 
Wire the resistors into the 
circuit and remove the 
jumpers. 

Check decoder operation 



by setting the generator to 
various low group frequen- 
cies. The circuit should hold 
in the proper state each time. 
Ground Ul-8 and check the 
high group decoder. 

!f you have access to a 
frequency counter with a 
high input impedance, you 
can use an alternate method 
to set up the decoder. 
Connect the counter to pin 6 
of Ul or U3. Select resistors 
so that the vco runs at the 
tone frequency in each case. 
This method saves some time 
and makes it easier to set 
single-turn pots. 

This completes the align- 
ment. Use a touchtone pad to 
check that the binary and 
one-of'Sixteen outputs are 
corrrect as shown in Table 2. 
The decoder is now ready for 
operation. There are some 
pitfalls to avoid in making it 
work in your system, how- 
ever. 

Interfacing the Decoder 

The ideai input sigrral is a 
pair of sine waves. Most 
touchtone pads use digital 
techniques to generate the 
tones and do not produce 
sine waves. With these signals, 
the decoder needs a higher 
level than it would with sihe-- 
waves and does not respond 



Tone frequency 


Capacitance (ch 


osen) 


Resistance (calculated) 


697 Hz 




0.22 uF 




7.174k Oh 


ms 


770 Hz 




0.22 uF 




6.494k Oh 


ms 


852 Hz 




0.22 uF 




5.S69k Oh 


ms 


941 Hz 




0.22 uF 




5.31 3k Oh 


ms 


1209 Hz 




0.1 uF 




9.098k Oh 


ms 


1336 Hz 




0.1 uF 




8.234k Oh 


ms 


147? Hz 




0.1 uF 




7.448k Oh 


ms 


1633 Hz 




0.1 uF 




6.736k Oh 


ms 


Table 7 


. Calculated values for resistors R3 to RIO. 




Touchtone Key 


Tones Used 


BCD Codes 


Decoder Outputs 










Binary Hexadecimal 


1 


LI, HI 




0001 


0000 





2 


LI. H2 




0010 


0001 


1 


3 


L1, H3 




0011 


0010 


2 


4 


L2, HI 




01 00 


0100 


4 


5 


L2, H2 




0101 


0101 


5 


6 


L2, H3 




0110 


0110 


6 


7 


L3, HI 




0111 


1000 


8 


8 


L3, H2 




1000 


1001 


9 


9 


L3, H3 




1001 


1010 


A 





L4, H2 




0000 


1101 


D 


m 


L4, HI 




none 


1100 


C 


# 


L4, H3 




none 


1110 


E 


A 


LI, H4 




none 


0011 


3 


B 


L2, H4 




none 


0111 


7 


C 


L3, H4 




none 


1011 


B 


D 


L4, H4 




none 


1111 


F 



Table 2. Comparison of BCD code and decoder output code. 



quite as quickly. Due to line 
losses or receiver audio 
response, the tones of a pair 
may not be equal in 
amplitude. Also, noise and 
distortion can cause faise out- 
puts. The best prevention for 
these problems is to use band- 
pass filters follovi'ed by 
compressors for both the low 
group and high group tones. 
The block diagram of such a 
system is shown in Fig. 4. 
These problems are discussed 
in more detail in references 1 
and 2. A delay circuit like 
that shown in reference 2 can 
help prevent falsing. Of 
course, if you want to drive 
ioads drawing more than a 
few mA, you will need tran- 
sistors and perhaps relays. 

Finally, take a look at 
Table 2. As you can see, 
because of the way the touch- 
tone keyboard is organized, 
my decoder cannot produce 
true BCD outputs. The keys 
are encodfed and decoded in 
rows from top to bottom: 1, 
2, 3, A, and so on. There are 
possibilities in using a touch- 
tone pad to control a home 
computer, but i.t would take 
some code conversion hard- 
ware. 

Conclusion 

The scanning touchtone 
decoder I've described uses a 
small number of ICs and 
requires only a single 5-voit 
supply. While it is slower than 
the standard type of decoder, 
it is reliable and uses readily 
available parts. It compares 
favorably in price with the 
stan'dard decoder. It has fairly 
good immunity to noise and 
distortion and is easily pro- 
tected if these are a problem. 
Keep its limitations in mind 
and you will get good service 
out of it. ■ 

References 

1 . "Autocall 76," C. W. 
Andreasen WA6JMM, 73 
Magazine, June 1976, pp. 52-54. 

2. "Toinard a More Perfect 
Touchtone Decoder," J. H. 
Everhart WA3VXH, 73 Magazine, 
Nov. 1976, pp. 178-181. 

3. "A Scanning Touchtone Digit 
and Word Decoder," Carl F. 
Buhrer W1GNP, QST Magazine, 
Jan. 1976, pp. 34-37. 

4. Signetics Oatabook, 1972 or 
later edition. 



180 



A sleek graceful sailing vessel glides across the sometimes green, 
sometimes blue Caribbean. The cargo: you. And an intimate group 
of lively, fun-loving shipmates. 

Unifoim of the day: Shorts 

and tee shirts. Or your bikini 

if you want. And bare feet. 

Mission: A leisurely cruise to 

remote islands with names 

like Martinique, Grenada, 

Antigua— those are the 

ones you've heard of. Before 

the cruise ends, you'll 




know the names of many 

more. You'll know intimitely 

the enchanting different 

mood of each . . . and its 

own beauty and charm. 




Life abt)ard your big 
sailing yacht is informal 
Relaxed. Romantic. 

There's good food. 
And 'grog] And a few 
pleasant comforts. . . 
but any resemblance 
to a plush pretentious 
resort hotel is -^ 
accidental. 

Spend 6 days 
'exploring paradise. 
Spend six nights watching the moon rise and 
getting to know interesting people. It could be 

the most meaningful experience of your life 
...and it's easily the best vacation you've had. 

A cruise is forming 
now. Your share from 
S290. Write Cap'n Mike 
for your free 
adventure booklet 
in full color. 

Come on and live. 





Windjammer Cruises. 



W10 



P,0.BO)(120, Dept. Miami Beach, Florida 33139 



T81 



Ron Warren WA2LPB 
118 Hamlet 
FredoniaNY 14063 



Fundamentally^ basically, 
and first of all, I'm 
cheap. If there is a cheaper or 



Hufco 
Counter Kit 



-- report from a happy user 




iess expensive way of doing 
something, Til try it. Perhaps 
that's why the Hufco "Easy 
$25 Counter Kit" caugtit my 
eye (my eyes are located in 
my wallet). 

After painfully shelling 
out the coin and placing my 
order in the mail, I settled 
down for a long wait. Wonder 
of ail wonders, within a week 
I received an acknowledg- 
ment of my order and a note 
that it would be six weeks for 
delivery (who ever acknowl- 
edges orders nowadays?). In- 
cluded with the note was a 
list of the parts required for 
the kit so I could start "ac- 
quiring" the parts. 

Perhaps this is the lime to 
explain that this is a rather 
unique "kit" in that it does 
not include any parts , . . just 
the PC boards, a precut cabi- 
net for the counter, and an 
instruction manual. 

Through the abundance of 
an overstuffed junk box and 
the cultivation of friends, 
most of the parts were gradu- 
ally collected- One traumatic 
experience was having to or- 
der the XAM3^2 readouts. 
The only readouts suitable 
were installed in a friend's 
clock, and he adamantly re- 
fused to part with them 
(cheap!). 

After six weeks of waiting, 
the counter didn't come, but 
■ 1 did receive a nice letter 
explaining about the delay — 
UPS strikes, delayed ship- 
ments from suppliers, etc. I 
also received a complimen- 
tary .^copy of their new pubSi- 
cation Channel 51. This 
rather well done magazine is 
obviously aimed at CBers 
who wish to convert to ham 
radio. This gesture made the 
following weeks of waiting 
more palatable, just knowing 
that someone somewhere 
knew that I had an order 
coming. 

Sure enough, one day a 
package arrived, and I was 
able to inspect my new 
TWS-006 counter kit. The 
cabinet was extremely well 
built with a nice silk screened 
front panel reminiscent in 
color of the old hleathkit 



182 



brown and beige. 

The PC boards were the 
biggest surprise. I had ex- 
pected rather rough boards at 
that price. Not so. 

These were doubic-sided 
boards with piated-through 
holes. Clear sharp traces gave 
plenty of room for even the 
klutzicst soldering iron 
mechanic. The component 
placement is clearly screened 
on the boards, and the one 
small mistake (a reversed in- 
dex mark for one of the 
7447s) is clearly called to 
your attention in the manual. 

While the manual itself is 
not quite what I'd call Heath- 
kit quality, it is adequate to 
insure correct assembly. It 
not only gives a step-by-siep 
procedure for assembly and 
interconnections, it also gives 
a good presentation of the 
theory of operation and a 
method of troubleshooting in 
case of any malfunction. 
Various options are discussed, 
including adding a prescaler 
for VHF or UHF operation. I 
ended up purchasing their 
prescaler board ($4.00) for 



future addition. 

The only drawbacks I ran 
into during construction are 
quite minor. The resistors 
used for the layout must have 
been 1/8 Watt units since my 
1/4 Watt resistors were some- 
what oversized. This resulted 
in a less than picture perfect 
board when finished, with 
leads wrapped back under 
components. Abo, I'd like to 
know where they found 3/8" 
diameter 1000 uF capacitors 
on their silk screen layout. 
Mine are larger, but by ex- 
tending leads, I was able to fit 
them in. These are all cos- 
metic complaints and don't 
affect the assembly of the 
unit. 

The actual smoke testing 
of the unit was very disap- 
pointing ... it worked. I 
couldn't beiieve it ... I just 
plugged it in, and it worked 
. . . very anticlimactic. Other 
than adjusting the trimmer 
for exact frequency, there 
were no other adjustments or 
tuning required. Unless 
you've built a lot of kits 
before, you can't realize just 



how frustrating this can be. 
Half of the fun of kits is in 
troubleshooting the darn 
things after you've built 
them. I remember one clock 
kit that was over six months 
of fun . . - but that's another 
story. 

The unit isn't the most 
sensitive I've ever seen, but 
it's not that bad either. 1 was 
able to trip it at less than full 
output from my Measure- 
ments Model 80 signal gener- 
ator all the way up to 57 
(ViHz. By picking and selec- 
ting 74LS90 ICs for the first 
three decades, I was able to 
bring the sensitivity down 
somewhat, but even as-is it is 
quite usable. I was able to 
read my 25 Watt CW trans- 
mitter on 21 MHz from a- 
cross the room with just a 
clip lead as a probe. 

Accuracy seems to be as 
good as six digits will allow. 
It counts the crystal output 
from my BC-221 as 2.00001 
with the last digit varying 
from 1 to 2 to on alternate 
counts. Warmup does noi. 
seem to affect it at all. 



Options that I plan to add 
to my counter are nicads for 
portable operation and the 
prescaler as soon as i can 
scrounge up a 95H90 chip for 
it. The company also offers 
an optional input which fea- 
tures the ability to "with- 
stand the full unloaded out- 
put from a transceiver on 28 
MHz for 20 minutes." Since I 
already have a dummy load, 
and rarely load my trans- 
mitter into my counter, I 
don't plan on adding this 
option. Oh yes, it also in- 
creases the sensitivity to some 
extent or something like that. 

In conclusion, I would 
recommend this counter to 
anyone who has a need for a 
cheap counter, or to anyone 
who is cheap and needs a 
counter. Seriously, it per- 
forms as well or better than 
commercial counters costing 
several times as much. If you 
have a well stocked junk box 
(or a friend who has one), 
you can bring the cost of this 
counter kit to well under $40 
and still have the convenience 
of a well designed kit. ■ 




from page 6 

pass along your experience through 
the pages of 73 . . . write. 

One of the reasons ham equipment 
has been in such short supply has been 
the drain of sales to HF CBers. Many 
of the ham dealers are selling Yaesu 
and Kenwood transceivers to CB 
dealers (usually after converting the 
rig to work on the 27 MHi band). 
These dealers sell the rig to a CBer at 
the full list price (or more), often 
compiete with an amplifier. 

A few dealers make every effort to 
see that this ham gear does not end up 
in a CB shack — with Tufts Elec- 
tronics being one of trie leaders in this 
crusade. The manufacturers and 
importers of ham gear are unable to 
stop selling to the dealers who are 
abusing us, due to restraint-of-trade 
laws. There has been a move to get 
dealers to demand proof of a ham 
ticket before making a sale, but this 
won't cure anything, because the 
deaiers who are selling ham gear for 
CB use know damned well what they 
are doing and are not about to stop as 
long as they can make an extra buck 



EDITORIAL BY WAYNE GREEN 



this way. If you can figure out any 
workable scheme to make it unprofit- 
able to sell to CBers, then you'll have 
a good plan to stop this practice. 

In the meanwhile, let's be vigilant 
and keep the CBers from twisting the 
dials of their transceivers to a ham 
band. What they do on the 27 MHz 
band is honestly none of our business 
at present — and we may be better off 
in the long run because they have 
established such a strong foothold 
there. What if the ITU (WARC) con- 
ference actually turns out as most of 
the knowledgeable hams of the world 
are predicting . . . with the loss of all 
HF ham bands? In thai case, the 27 
MHz HF CB band may be the only HF 
"ham" band we've got left. 

THIRD ANNUAL 
INDUSTRY MEETING 
The 1978 ham manufacturers and 
dealers conference will he held in 
Aspen, Colorado, from January Sth to 
15th. In addition to the usual break- 
fast and dinnec meetings which have 
made this yearly conference such a 
success, there will be three forum- 
workshops. Chuck Martin, the owner 



of Tufts Electronics, will conduct a 
workshop on things store managers 
should know, such as how to sell ham 
equipment, how to develop a compre- 
hensive line of equipment to sell, and' 
how to drum up a lot of local business 
using catalogs, newspaper advertising, 
radio, and television. 

There will also be a workshop on 
how to write ads, catalogs, and other 
sales literature. This will also include a 
comprehensive workshop on media 
selection and planning; how to pian 
your advertising budget, ho* to select 
sn ad agency, and how to save sub- 
stantially on your advertising. This 
workshop could well pay for the 
entire conference. 

Each of the workshops will prob- 
ably take two evenings due to the 
comprehensiveness of the material. 
Even the old-timers will find a lot of 
value in these workshops. 

There will be a forum devoted to 
crystal ball-gazing — second-guessing 
the future so you can take maximum 
advantage of what is going to happen 
next year. 

The conference vi\\\ be convening at 
the Continental in Aspen — it's a little 
tacky, but it does have a nice heated 
pool and a sauna, and it is right in the 
heart of town. Accommodations go 
early, so if you want to take advan- 
tage of this third annual ham industry 
workshop, better make your reserva- 
tions with the hotel. There may even 
be snow this year. 



SOME OPENINGS 
AT 73 

It should he no news that 73 is 
growing — and so is Kilobaud. This 

■means that we need more people to 
wmrk on the magazines and the other 
plans afoot. We do have a need for 
some hams with experience in writing 
and construction to help test new 

.equipment and write it up ... to work 
on books . . . help with articles . . . 
etc. This is something that really has 
to be done right here in New 
Hampshire, which is one of the nicest 
places in the country to live. 

We also need help in working on 
microcomputers . . . testing programs 
and seiling them . . . checking out the 
newest equipment . . . things like that. 
A ham with a lot of experience in 
FORTRAN IV would find some 
interesting work. We also need help in 
support jobs such as management, 
marketing, sales, etc. 

We're looking for peopie with in- 
telligence, with some background, 
who don't smoke, and who are willing 
to go all out to became tops in their 
jobs. The pay is reasonable, and can 
be most rewarding if an outstanding 
job is done. Working for a small firm 
such as this gives you an excellent 
opportunity to grow and iearn . . . 
something you just can't get in a 
larger business. 

All you have to do is look at some 
of the 73 graduates , , , one is editor 
of a well-known magazine . . . another 

Continued on page 185 



183 



V/illiam Hosking W7JSW 
8626 E. Clarendon 
Scottsdsle AZ 8S251 



A Single Tone 
Can Do It 



- - simple tone control system 



In the process of putting 
together a repeater of my 
own, I found that I wanted to 
perform a simple ON/OFF 
auxiliary function via the 



P 



r 



1 !k;i 1« 



IMPUT ) 












i" 



repeater input. In my case, it 
happened to be turning an 
aural frequency indicator on 
or off, but the function could 
be almost anything. From 
previous experience vvith such 
a used control in another 
location, I decided on the use 
of two single tones — one lo 
turn the function on and one 
to turn it back off. Armed 
with this idea, I dug into my 
data books, experimented a 
little, and arrived at the 
circuit described in this 
article. 

Circuit Operation 

The basic 567 decoder cir- 
cuit is shown in Fig. 1 (a). By 
feeding the output back to 
the last stage at pin 1 (output 



filter), the output can ^be 
latched on. The circuit can" 
then be unlatched simply by 
pulling pin 1 high momen- 
tarily. A general purpose PNP 
■transistor can be hooked- up- 
to do that task. 

I then added another 567 
decoder to get the unlatch 



signal. The output of this 
decoder turns on the PNP 
transistor just mentioned, 
thus unlatching the circuit. 

The complete circuit is 
shown in Fig. 2, With the 
values shown, the decoders 
should tune over most of the 
normal single tone range. 
Depending on the length of 
tone burst available, the 
values of C3, 4, 6, and 7 
might have to be adjusted 
slightly if the decoder does 
not respond fast enough. 

Adjustment 

When wiring is complete 
and checked, then power can 
be applied and the circuit 
checked out. A frequency 
counter or accurately cali- 
brated scope is necessary to 
adjust the centei' frequency 
of the 567 decoders. Attach 
the counter or scope to pin 5 
of Ul and then adjust R1 for 
the desired "ON" frequency. 
In my case, 1 used 1800 Hz. 
Now put the counter (scope) 
on pin 5 of U2 and adjust R4 
for the desired "OFF" tone. 
Again, in my case, I used 
1950 Hz. 

Now connect whatever 
load you intend to use to pin 
8. I have shown a relay since 
that is the most common 
usage. Connect an audio 
generator to the input and 
apply about 100 mV of 1800 
hi,; audio. The relay (load) 
should activate and should 
remain activated when the 
tone is removed. Now set the 
atJdio aenerator to the 



Fig, 7. (a) Basic 567 decoder circuit. Resistor R1 and capacitor 
C3 set the basic operating frequency or detection frequency. 
CI and C2 are loop filters and their values affect response time 
and detection bandwidth, (b) Latching circuit, feeding the 
output (pin 8) back to the input of ttm final stage (pin 1). The 
latch can be released by pulling pin 1 to Vcc momentarily. 




Fig. 2. Complete schematic of the two tone latching decoder. 



184 



r 



.o 




~] 



RZ D2 
o— vw — o o ►* * °~ 



N-LOAD 





H^ 




H3 




f 1 — "^ — 1 




( 


C5 


C7 


UZ 








L 


< 


1 


9 c 



R4 
o Wv o 



tir 



_l 



W?JSW 







CONTACT Rg,D. 
TEMPE AZ i^ 

A. A— o 



"Ol-F" frequency (1950) and 
apply that to the input. If all 
goes well, the load should 
de-actlvate. 

Operation 

I have my decoder oper- 
ating from a 1 2 volt line and I 
am using a 24 volt relay as 
the load. The repeater re- 
ceiver audio is fed to the 
audio input and I use the 
relay contacts to turn my 
tone frequency indicator 
on/off. The only thing you 



have to watch pretty closely 
is the input level to the 567s. 
The best operating point is 
about 150 mV. More will 
cause falsing and less won't 
operate too reliably. 

Conclusion 

A layout for a printed 
circuit board and the parts 
arrangement are shown in 
Fig. 3. The board is available 
from CONTACT, 35 W. Fair- 
mont Dr., Tempe AZ 85281, 
for $5.00 ppd. 



Fig. 3. (a) Parts layout for the prototype printed circuit board. 
This is tiie parts side of the board; the copper is on the other 
side, (b) Full size PC pattern for the prototype circuit board. 
Production boards, available from CONTACT, Inc., 35 W. 
Fairmont Dr., Tempe AZ 8S28I, will probably be slightly 
larger to moke parts placement easier. 



With cross-banding now 
approved, 1 may put one of 
these circuits on one of our 
local repeaters to provide a 
user accessible cross-link 
between 450 and 2 meters. 
Good luck and write if you 
have questions, but with 
today's postal rates, please 
enclose an SASE if you want 
a reply. ■ 



Parts List 

CI -0.5uF 
C2, C5 - 0.33 uF 
C3, C6- lOuF/IS V 
C4, C7-22uF/15 V 
D1, D2- 1N4001 
R1 , R4 — 1 5k PC trimmer 
R2-20k% W, 10% 
R3- 10k 74 W, 10% 
Q1 - 2N3905/3906/ 
. MPS6B21/2N2222, etc. 
U1, U2- 567 decoder 
RY1 - Relay to suit Vcc used 




from page 183 

is the ad manager of s new magazine 
and is reponedly pulling down over 
SIOO.OOO a year . . . another has his 
own magazine now, which is worth 
over $1 millian . . . etc. The fine forms 
to the left. 

WEW IDEAS NEEDED 
Despite the sudden growth of ama- 
teur radio as a result of the club 
programs to get in new licensees, 
attendance at hamfests seems to haue 
been dropping off. How come, with 
more hams than ever before, we have 
fewer going to hamfests? 

There are probably several reasons 
. . . such as the high cost of getting 
into hamfests ... a iaclt of any real 
promotion of many of the events, 
with more dependence on prizes than 
anything else to draw attendance. The 
recent AR RL event at Hartford, home 
base for the League, is a case in point. 
The show was well-organized, and 
promoted in QST . . . yet the turnout 
was disappointing. The $6.50 entrance 
fee was cited by many as prohibitive 
for the youngsters . . . and, indeed. 



EDITORIAL BY VJA YNE GFIEEN 



there were very few kids running 
around the show. Most of the fellows 
I saw were chaps I have known for 
thirty or forty years. 

You really can't expect to get 
$6.50 from kids to see a dozen or so 
exhibits [mostly by dealers trying 
hard to sell gear) plus a talk by 
Dannals. Oh, add $20 if you want to 
take in the dinner. 

We need ideas. ""If you have some 
ideas that have worked with a hamfest 
in your area, why not put them dov;n 
on paper and send them along so the 
rest of us can benefit? We'll try to get 
all the good schemes pubiished in 73. 

CB TO TEN 

Owners of Standard Horizon 29 CB 
rigs can reioice, for Standard has a 
dandy ten meter conversion for the 
set. If you have the 23-channel set, as 
I have, you can get a 40-channel 
switch from your local Standard 
dealer and get 40 channels on ten 
meters. 

Standard has a coiiversion sheet 
available, "Procedure for 10 Meter 
Conversion of Horizon 29." This gives 
the details of where to cut the foil on 



the board and what parts to add and 
change. The changes are minimal, 

The result is a rig which works on 
ten meters, starting at 28,965 and 
going up in the same increments as the 
CB channel spacing to 29,405 MHz. 
That's just two MHz above the 11 
meter channel frequencies . . . and 
that change makes a lot of sense. If 
you start much lower, you run into 
the higher povvered sideband stations 
in the lower 350 kHz of the phone 
band. 

Give a call on 28,965 on Sundays at 
1000 PDT and you'll probably get an 
answer from the bunch out in L.A. on 
the channel ... if the band is open. 

MORE ARTICLES 
Perhaps you'd like to see more 
microcomputer articles 'm73 . . . well, 
write 'em. In Kilobaud, I am exploring 
the advantages of getting into this new 
field and how to do it in my editorials 
. . . but you can't do much in micro- 
computing if you don't know any- 
thing about microcomputers. Let's see 
a lot more articles on microcomputing 
for 73 . . . and it doesn't hum to bring 
ham applications into the act. 

MARY PLEADS 
WITH YOU! 
A few readers, despite every effort 
to make reader service simple, have 
been screwing things up. The worst 
complaint from Mary, the lovely gal 
who handles our reader service, is that 
there are dozens of readers who are 
not sending in their cards. Yes. I know 



this is difficult to believe, since you all 
know haw much store advertisers put 
in getting requests for literature. They 
put even more store in your buying, 
"of course, so don't let reading litera- 
ture stop you from buying. 

The other gripe is that a few readers 
are making a mess of ttic- card with 
crosses and blotches. Mary says to 
- circle the number, not obliterate it . . . 
puleezel Mary also requests that you 
sign your name and address clearly . . . 
and if you're not sure, please ask 
someone. 

THAT AUGUST QST! 
If yoti are in the Maryland, D.C., 
Northern Virginia, Western Penn- 
sylvania, or Western New York areas, 
be sure you don't miss getting your 
August subscription copy of QST. 
That's your August subscription copy, 
not one from a store . . . don't miss it. 



/f 



ivlxatdoyou 
g\vz the man 
who has 
ci^erything? 



# 



185 



John U. Franks WA4WDL 
Apl. 225 

1006 WesamoTeland Ave. 
Norfolk VA 23508 



plified for geosynchronous 
satellites to: 

sin(LI + D1 



Eye On 
the Weather? 

-- following weather satellites 



Interest in the geosyn- 
chronous weather satel- 
lites is increasing rapidly. 
Many fine articles have 
appeared on the construction 
of receivers, converters and 
displays. Plotting charts are 
available for the low orbit 
satellites. But very little infor- 
mation is available on 
locating the geosynchronous 
satellites. This article presents 
a method of calculating the 
azimuth arid elevation angles 
needed to point your antenna 
and, also, an alternate 
graphical technique. 

To aim your antenna, you 
need the following informa- 
tion: 

1. Your latitude and 
longitude. 

2. The longitude of the 
satellite subpoint. 

The result of the computa- 
tions will be the desired eleva- 



tion and azimuth. Elevation is 
the number of degrees the 
antenna must be tilted above 
the horizon. Azimuth is the 
bearing angle the antenna 
should be turned from true 
north. 

Let us fir^st calculate the 
azimuth angle. To do this, 
construct a great circle route 
which passes through your 
location and the satellite sub- 
point. The latitude of all 
geosynchronous satellites is 
zero degrees. This great circle 
is used to determine, first, the 
distance from the satellite 
subJDoint to your location 
and, then, the desired 
azimuth angle. Fig. 1 shows 
the navigation triangle from 
which the distance to the 
subpoint, D, and the azimuth 
angle, A, is determined. From 
Bowditch^ we find that: 
Hav D = 




SATELLITL- SUBPOI/JT 



Hav( L01-L02') coslLll cos IL2) + 
Hav/(,L1-t2|l 

Where: 

HavDis/2[1-cos(D)]; - . 
LI is your latitude; 
L2 is the subpoint latitude 
(zero); 

L01 is your longitude, 
degrees west; and 
L02 is the subpoint longi- 
tude, degrees west. 

This equation was de- 
veloped for navigation using 
Napier's Laws for spherica]__ 
triangles and, hence, is 
strange in appearance. How- 
ever, making the necessary 
substitutions we find: 

cosfD) = coslLII cos(L01-L02) 

From this, it is easy to 
find D. D is e,'>;pressed in 
degrees. Having found D we 
can now determine A, the 
azimuth angle, by: Hav A = 
sec(Ll) csc(D) |Hav(90° 
- L2)-Hav(|D -90°+ LI i)] . 

This equation can be sim- 



cos(A) = 1 



cosdU sinlO.I 



If the subpoint longitude 
is less than your longitude, 
the azimuth angle is A. If the 
subpoint longitude is greater 
than your longitude, subtract 
A from 360 to obtain the 
azimuth angle. 

If you arc still with me, 
the elevation angle is calcu- 
lated next. A drawing of the 
great circle path is laid out in 
Fig. 2. The desired elevation 
angle is labeled B. Here we 
have a triangle with two 
known sides, and the angle 
between them is known. One 
side is equal to the Earth's 
radius, 3,440 miles. The other 
side is equal to the sum of the 
Earth's radius and the satel- 
lite's altitude, 22,300 miles. 
Using the law of cosines; 
B = 90' ■ D - 

/ 3440 



sin(Qi \ 
40co5(Dl J 



'■•'""■ ^^ 25740 -3440: 

Let's examine some hypo- 
thetical cases of a station at 
37° N. latitude and 76° W. 
longitude, desiring to receive 
ATS-I at 149" W. longitude 
and ATS-3 ai 70'' W. longi- 
tude. 



ATS-I : 




cos{D) = 




cos(37")cos(-73'l - 




. 798 X. 292 = 


-- 


.233 




D = 76.5' 

co-(A)-1 si"" 13.5) 


'^*'''^' ' cos{37M 


sin(D) 


.917 


,1S2 


' .798 X. 972 


A= 100,5° 




But ATS-l's 


longitude is 


larger than the 


station's lon- 


gitude, so: 




Azimuth angle = 




360° 100.5° - 




259.5° 




B = 90" - 76.5° - 




/■ 3440sin(76.5°l \ 
arc t=n 1^ ^5740 3440cds(76.3 1 J 


B = 90' ■ 76.5° - 





^TOJS LOCATION 

5 (ELEVATION ANGLE) 



Fig. 1. Navigation triangle formed by your location, the North 
Pole, and the satellite subpoint. 




— GREAT CIRCLE ROUTE 



Fig. 2. Geornetry used for calculating the elevation angle. 



IS6 



Lj>L, 
l.S<L), 


340 
^20 


= 


320 




tis 


300 
60 




^ 


230 
SO 


7f0 

T 1 


260 

TOO 






2 

1 


40 
10 




■ 


220 
140 


-L 


20D 


T^-i-^-T-^^ 


^=!=T= 




= 


Eti^F^4=^f^^ 








L_ 






'. 






h; 




^4j^_^ 







. 


J^ 


^_^, l_ 






! )-, 




If 


! 1 







J 


— 









— 




1 





-t 


-r^l,„ 




! 1 


























1 1 


1 






li;;''" 










i i 




























1 




1 








1 il 














J 














1 1 


















|1! 






























1 
















Ill 








1 
























1 










r" 




i 


1 




















































1 


















































































































1 












































90- 




1 




























1 
















1 




i 




























(1 '" 






1 


1 








t 
































il 






1 










[ 
































li 


L Tn. 


! ! I 








1 




'-II 


















l-H| ■"■ 


H 










[ 










. I 


















a 






il i 




















1 




















60 


!!i ! i ; 


















i 


























nil)! 




1 












1 




























ilM ; ! 1 










1 i 






1 


























i 




[ 










I 


1 




11 i i i M 


. 











1 





\ 


_ 


J 


_ 






30- 


■ ' ; ' — ^ ^ — j 


-1- 


— 


— ' 


— 


1 [ 




1 


- 


— 


~ 


— p- 


— L 


Li 


























'-.- ......^ . I....:.... 7^ + :r.— ■ 


—7.- 


^L^^-rirl 


-. , : ■ 


— 


— ttI 


--— 


— 


— 




- 




^ 


-^_t! 



F/^. 3, Simplified d'Ocagne chart. All scales are expressed in 
degrees. L^ - satellite subpoint longitude; Ly ~ your longitude; 
A = azimuth angle; Z ^ zenith angle; L = your latitude; and H 
= 90" -1. 



arc tan 



3440 x .972 
25740 - 3440 x .233 



90° - 76.5° - 7.6° 
Elevation angle = 5.9° 

ATS-3: 

cos(D) = 

cos (37°) cos(6°) = 

,7S8x.994 = 

.793 

= 37.5° 

costA) = 

sin (74.5° 



cos(37°) sin(37.5°) 

-^^ = . 982 

.798 X. 609 



Azimuth angle = 168° 
B = 90° -37.5° - 

arc tan / 3440 sin (3 7. 5°) 

i^25740-3440cos(37.5°J 

B = 90° -37.5° - 

/ 3440 X .609 
arc tan y ^5740 . 3440 x .793 

90° - 37.5° - 5.2° 

Elevation angle = 47.3° 

While the mathematical 
approach is precise and 
accurate, a much simpler 
graphical technique can be 
used with little loss in 
accuracy. Fig. 3 is a sim- 
plified d'Ocagne diagram 
from Bowditch, which can be 
used to solve spherical 
triangle problems by drawing 
straight lines and doing 
simple subtraction and addi- 
tion. Each axis has been 
divided according to the 
haversine of the angles. The 
scales in Fig, 3 are simplified 
to reduce confusion. The 
graph applies only to stations 
in the Northern Hemisphere. 



The use of the graph is best 
explained with examples. 
Taking the same examples as 
before, ATS-1 and ATS-3, let 
us proceed. 

Step I: IVlark your latitude 
on both the left and right 
vertical scales. Connect the 
two marks with a straight 
line. 

Step 2: Subtract your lon- 
gitude from the satellite sub- 
point longitude, L; - Ly. If 
the result is positive, proceed 
to step 3. If the result is 
negative, add 360 to the 
result to get a positive angle 
between 0° and 360°. If ILj- 
Lyj is greater than 90°, the 
satellite is below your hor- 
izon and cannot be received. 

Step 3: Take the result of 
step 2 and make a mark on 
the top axis. Drop a vertical 
line from this point to the 
line drawn in step T From 
where the two lines cross, 
draw a horizontal line to the 
left scale and note the read- 
ing, Z. This value of Z can be 
converted to the elevation 
angle B by Table 1. If Z is 
greater than 80°, the satellite 
is below your horizon and 
cannot be received. 

Step 4: Subtract the value 
Z from 90°. The result is 
labeled H for convenience. 

Step 5: Subtract H from 
your latitude, ignore the sign 
of the result. IVlark the result 



on the left vertical scale. 
Similarly, add H to your 
latitude, and mark the right 
scale accordingly. Connect 
the two marks with a straight 
line. 

Step 6: Where the line 
from step 5 crosses the 90° 
horizontal line, extend a line 
vertically to the top scale. If 
the satellite subpoint longi- 
tude is greater than your lon- 
gitude, use the upper scale. If 
not, read the lower scale. The 
reading is the desired azimuth 
angle. The elevation angle was 
obtained from Table 1 in step 
3. 

The worksheets for ATS-1 
and ATS-3 (see Figs. 4 and 5) 
demonstrate that the errors 
are typically less than one 
degree. I find this graphical 
method to be much faster 
and easier on the brain than 
the exact mathematical 
method, and the errors are 
much less than the bearn- 
width of practical antennas. 

Aligning the actual anten- 
na mount, in order to use this 
data, can be difficult. There 
are two methods I find useful 
to calibrate the azimuth scale. 
The elevation scale is easily 
aligned using a spirit level. 

The first, and simplest, 
method is to use the North** 
Star, Polaris, Rigging a sight 
on the mount and bore sight- 
ing the mount with Polaris at 
night will bring the mount to 
an azimuth angle of 0° ± /2°. 
However, every time I have 
attempted to use this method 
I have found a tree, house, or 
even a mountain between me 
and Polaris. 

The alternate technique 
requires a copy of the Nauti- 
cal Almanac and the ability 
to see the noon position of 
the sun. f\ Nautical Almanac 
can be purchased at most 
marine outlets, or a copy is 
usually available at a local 
library. When you open the 
almanac, it appears to be a 
vast array of tables. Each 
page pair covers three days. 
The column we are interested 
in is labeled "Sun," Under 
this heading are two sub- 
head ings, "Dec." and 
"GHA". "Dec." is an abbre^ 
viation for declination, which 





Elevation Angle 


z 


(degrees! 





90.0 


2 


87.7 


4 


85.4 


6 


83.0 


8 


80.3 


10 


78.5 


12 


76.2 


14 


73.9 


16 


71.6 


IS 


69.3 


20 


67.0 


22 


64.7 


24 


62.5 


26 


60.2 


28 


57.9 


30 


55.7 


32 


53.4 


34 


51.2 


36 


49.0 


38 


46.7 


40 


44,5 


42 


42.3 


44 


40.1 


46 


38.0 


48 


35.8 


50 


33.6 


52 


31. B 


54 


29.3 


56 


27.3 


58 


25.0 


60 


22.9 


62 


20.8 


64 


18.7 


66 


16.6 


68 


14.6 


70 


12.5 


72 


10.4 


74 


-., 8:4 


76 


6".4 


78 


4.3 


80 


2.3 


Table 


/. Antenna elevation 


angles 


for Z values from 0° to 


80\ 





is not of im.portance for our 
.work, GHA is an abbreviation 
for Greenwich Hour Angle. 
GHA is the longitude of the 
solar subpoint. "Dec." is the 
latitude of the solar subpoint. 
Assuming you are in the 
continental United States, 
when the sun's GHA is equal 
to your latitude, the sun is 
directly south, or at your 
180° azimuth position. To 
the right of the GHA column 
is a GMT column. To use the 
almanac, look down the GHA 
column for the date of inter- 
est until you find a GHA near 
or equal to your longitude. If 
the GHA matches your lon- 
gitude, the corresponding 
GMT is the time when the 
sun is directly south of your 
location. !f not, you must 
interpolate. Note that a 
difference of one hour in 
GMT corresponds to a change 



187 










2 Sit^^fc^- 
|1-H| 



F/i?, 4. ATS- 7 worksheet QTHis37° N., 76° W. Satellite is 
N., 149° W. L =3f; Ls-Ly= 149° - 76° = 73° ;Z^ 76.5°; H 
= 90° - Z= 13.5°; \L - H\^ 24°; L + H = 51°; A « 259° 
(259.5° calculated); B (from table) = 5.9° (5.9° calculated). 



of 15° in GHA. Taking the 
largest GHA less ttian your 
longitude, note the GMT. 
Subtract the GHA from your 
longitude. Divide this differ- 
ence by 1 5°, and multiply the 
resuit by 60 minutes (time, 



the number of minutes which 
must be added to the noted 
GMT to obtain the exact time 
when the sun will be due 
south. Fasten a stick on your 
antenna mount parallel to the 
antenna axis. When the calcu- 



not angle). This product is lated time arrives, point the 




Made from finest 

grade wtiite 

cotton with 

4 color imprint. 

OBDER NOW! 

(Supply Limiied) 

Only S5.50 ppd. 



To order your Computermaniiac Tee Shirts please use the Reader 
Service Card in the back of this magazine, or send your order 
indicating size (S, M, L, XL) & quantity and complete credit card 
information to; 

Computerrnaniac Tee Shirts • 73 Magazine 
Peterborough NH 03458 



|i-h; 




Fig. 5. ATS-3 worksheet. QTH Is 37° N., 7^ W. Satellite is 0° 



N., 70° W. L = 3f; Ls - Ly = 70" - 76° 



354°; I 



3 7. 5°; H = 90° -Z = 52. 5°; \L-H\ = 15. 5°; L+H = 89.5°; A ^ 
167° (168° calculated); B (from table) = 47.5° (47.4" 
calculated). 

stick at the sun by watching 
the stick's shadow (never 
look directly at the sun). 
Your azimuth scale can now 
be set to 180°. By the way, 
an error of one minute in 
time is an error of only K° in 



azimuth. ■ 

Reference 

Bowditch, Nathaniel, American 
Practical Navigator, H.O. Publica- 
tion Number 9, US Government 
Printing Office, Washington, 
1966. 



Social E/ents 



CLEARWATER BEACH FL 
NOV 19-20 
The Florida Gulf Coast Amateur 
Radio Council is holding its 2n(j. 
annual convention on Noverr^ber 19 
and 20, 1977 at the Sheraton Sand 
Key Hotel on Clearvjster Beach FL. 
Official attendance at our last affair 
was placed in excess of 2200, and this 
year we expect to double that number 
as we increase the number of activities 
and size of the convention. For more 
information contact: Fiorida Guif 
Coast Amateur Radio Council Inc., 
PO Box 157, Clearwater FL 33517. 

MASSILLONOH 
NOV 20 

The Massillon ARC 16th Annual 
Hamfest and Auction will be held 
Sunday, November 20, 1977, at a new 
location: Towns Pla^a Shopping 
Center in downtown Massillon, Ohio. 
Unlimited parking. iVjajor prizes given 
away. Starts 9 am - admission Si. 50 
at door. Mobile check-in 146.52 sim- 
plex. For brochure and map write to 
MARC, PO Box 73, Massilion OH 
44646. 

ELL1C0TTC1TY MD 
NOV 27 

The Columbia Amateur Radio 
Association (CARA) will hold its 



CAR A Hamfest on November 27, 
1977, at the Ellicott City Armory in 
EHicott City, IWarytarid. Program 
includes exhibits, flea market, prizes, 
and refreshments. All indoors. No 
tailgating. Talk-in on 147.99/39, 
146.16/76, 146.52/52. For more info 
contact CARA, PO Sox 850, Colum- 
bia MD 21044. 

OAK PARK Ml 
NOV 27 

The Oak Park High School Elec- 
tronics Club is presenting a Swap and 
Shop on " Thanksgiving Sunday, 
November 27, 1977, at Oak Park High 
School, Oak Park, Michigan 48237. 
Refreshments and door prices. Dona- 
tion, SI. 00. Table, SI -00. 

FORT WAYNE IN 
JAN 22 

The annual Fort Wayne Winter 
Hamfest will be held on January 22 at 
Shiloh Hall, north of Fort Wayne, 
from 8 am until 4 pm local time. 
Early parking is available and 28/88 
and 52/52 will be monitored. This 
yearly event is sponsored by the Alien 
County Amateur Radio Technical 
Society (AC.'ARTSI. Admission is 
S2.00 at the door. Table space is 
available at $1.50 per half table 
(about 4 feet). 



i 



H2iv Products 



from page J 68 

the vehicle dash panel with the micro- 
wave horn "peeping" through the 
windshield. The power piug simply 
plugs into the cigarette lighter. It is 
designed to operate from the 12 volt 
battery with either positive or nega- 
tive ground with low power con- 
sumption. The electronics is housed in 
a handsome 5-1/4" x 4" x 3-1/8" high 
steel cabinet with a black textured 
finish. 

The operator controls are inten- 
tionally limited to a single three- 
position switch with the following 
functions: 1) system test; 2) radar 
detection, visual indication only; 31 
radar detection, simultaneous audio 
and visual alarm. The Bird Dog has 
thus been designed to eliminate the 
troublesome, and usually unsatisfac- 
tory, gain adjustment control knob 
found on competitive units. The elim- 
ination of this gain adjustment also 
enhances the unit for out-of-sight 
mounting if the user so desires, such 
as under the hood with the microwave 
horn "peeping" through the grille 
opening. 

The unit features a high gain, die- 
cast, aluminum microwave horn and rf 
cavity tuned to 10.B25 GHz. A pair of 
microwave diodes are located in the 
cavity, one for modulation of the 
continuous rf carrier and the other for 
detection of the low-level radar signal. 

The detector diode drives a low 
noise, low level, metal paci^age, linear 
integrated circuit amplifier. The low 
noise and metal package along with 
otiier appropriate filtering and shield- 
ing virtually eliminate false triggering 
from spurious sources. The output 
circuit consists of a phase locked loop 
integrated circuit package whose 
bandwidth is controlled to ±B% of the 
local oscillator to virtually eliminate 
any unwanted frequencies beyond the 
range of the phase locked loop's local 
oscillator. The output driver drives 
both an audible buzzer and a red 
jeweled indicator light. 

The kit assembly is simple and no 
special training is required. The kit 
can be completely assembled in one 



evening. 

The Bird Dog kit, including a set of 
detailed plans for construction, sells 
for S49.95, or, if you prefer, S74.9S 
for a p reassembled and fully tested 
unit, plus $2.00 for postage and han- 
dling. A set of detailed construction 
plans can be purchased separately for 
£5.95 and is discounted from your 
purchase price when you purchase a 
Bird Dog kit. 

The Bird Dog is available through 
Micro Electronics, 1921 1-85 South, 
Oiarlotte NC 28208, telepiione (704) 
392-1705. 



NEW AND IMPROVED 

ELECTRONIC KEYER FROM 

HAM RADIO CENTER 

Years of experience in the manufac- 
turing of amateur radio equipment 
(the famous Ham Keys) are what is 
behind Ham Radio Center's new and 
improved electronic keyer . . . Model 
HK-5A. 

Outside, it features a trimmer 
cabinet color-keyed to match most 
modern amateur radio equipment, 
with all front-mounted controls 
{speed, weight, tone, and volume) and 
jacks for external paddle and/or 
keyer, plus external power. Inside, 
this battery-operated unit has an 
iambic circuit for squeeze keying, 
self-completing dots and dashes, a dot 
memory, built-in tone monitor and 
grid block, and direct keying. Bat- 
teries not included. Also, it can be 
used as a code practice oscillator with 
a straight key. 

For more information about Model 
HK-5A, write Ham Radio Center, Inc., 
8340-42 Olive Boulevard. P.O. Box 
28271, St. Louis MO 63132, or call 
(toll free) 1-800-325-3636. 



CW SPEAKER SYSTEIVI 
USES ACOUSTIC FILTER 

Skytec of Ukiah, California, is 
offering a loudspeaker unit designed 
expressly for CW. Employing a unique 
acoustic chamber resonator, the 
Skytec CW-1 combines good "single 
frequency" selectivity with a nice 




The Bird Dog. 




TheSkytech CW-1. 



tone shaping characteristic, 

-By filtering ■ right at the audio 
output to the room, the unit sup- 
presses hum, hiss, ringing, and miscel- 
laneous noises left in the audio by 
most receivers. The CW 1 adds a 
remarkable degree of selectivity to 
receivers without a sharp electronic 
filter, and it gives the best of receivers 
the most pleasant, "just right" tone 



output and bandpass for long QSOs, 
net operating, and band scanning, 
Skytec says. 

Priced at Si 9.95, the 314" by 614", 
2-pound unit is shipped with a con- 
necting cable. A front switch provides 
for bypassing the audio to the regular 
station .speaker for other than CW 
reception. Skytec, Box 535, Talmage 
CA 95481. 




Adirondack 
has It! 

Amateur Headquarters for th;^ Moftheast 

186-191 West Main Street • P O. Box 88 
Amslerdam, N.V. 12010 Tq! (5!81 B42-e350 
Juat $ minutos tram N,Y. Thruway ~ Exii 21 




The Model HK-SA keyer. 




OUSE 



969 Ball Ave.. 
Union, N. J, 07083 
(201) 964-5206 



SEND FOR FREE HOBBr HOUSE CATALOG 
LOWEST PRICES ON PRIME COMPONENTS 

Some Examples 



HIGH POWER TRANSISTORS 

factory Prime 

2N 3055 NPN (ITTTO 3 Case) 

2N JSS9 PNP [RCA TO-3 Case) ._ . _ 

DTS4iaNPN;GE TO-3 Caie). 

Eqijiv 10 ECG 162 

2H 1181 P^P|fiCA rO-BCasa] 



2/$1.00 
2/Sl 00 



2/Jl.OO 
2/S! 25 



IN 4148 SWITCHING DIODES 

Factoty Prime, Taped S Reeled 50/Sl.QO 

1000 MFD 30 Volt Electrolytic Cap Axial Leads 

5 for SI. 00 

CAPACITOR ASSORTMENTS 

Popular tsliK disc & low leakage up to & 

including 1 MFD 40 for $1.00 

Tubular Electrolytics Asst. 

from 1 MFO 10 2000 MFD 15 (or $1.98 



POTENTIOMETER ASSORTMENT 

IKm I03K . ... . 12/JIOO 

HELIPOT 

10 [jm, Wire Wound Potentiometer 

500 Ohms, 5 Walls, 1/2% Lineadly $198 

5 FT LINE CORDS 

6 torSi.OO 



250K SLIDE VOLUME CONTROLS BY MALLORY 
4/$1.00 



2 AMP CIRCUIT BREAKER 

Front Panel Mount Thmugh I/?" Diam&ter Hole 
120 VAC, 32 VBC, Trips at 2.7 jmps . ., 2/$l,00 

GRAIN of WHEAT type chic. min. 

Oisplay Lamps ■ Red oritthite 10 for SI. 00 

Impeiiancc Hatctiing Transformers 

■ Mini2!ure Audio f/pe - 15 for SI 29 

ORT REED SWITCH capsules 

Glass Sealed .5 amp 115 VftC 2b for $1.98 



5 volt, 6 Amp POWER SUPPLY KIT 
$12.95 complete 

Fixed: 6 Amp, 5 volt 1% Regulation 
Adjustable: S-t2 volts Unregulalnj 
Shorl Circuit f'rotection. Current Limiting 
KITINCLUttES: • Heat Sink 

• Transformer • Comp. Grade Filter Cap 

• Rejolatni • Output Power Transistors 

• Resistors * Capacitors 

• 4 Way Bindini Posts • Bridge RectfTiei 

• Line Con5 
Complete InsT/i/ctr'WJS & Di^grsms 



AMPLIFIER & SPEAKER MODULE 
$2.95 ea. 



• Not a kit — Ready for Mounting 

• 2'.i" Speaker, ! otim 

• 200 m* 12 volts 



' Adjustable range 



COMPUTER PRODUCTS 

ALL PRIME. FACTORY, NEW 

21L0M, RAM low power, 45 ons 8rorS12-50 

1?02A, EPROM Memory i-5 ws S4.95 Ci, 

2708, FROM 1 k i 3 wv 521.96 ea. 

8080A, Microprocessor 2 ws $995 ea 

PRICE BREAKTHROUGH! 



Terms and Conditions 

Ordets Shipped Withm 24 Hours. 

S5 (JO Minimum Order leleptione C Q.D 's a^cepled. 

J15 0Q Minimum Bank Amerrcaro/MasKrChar^e order 

Add $1.00 Postage (or orders under $10.00 

Outside Continental US. add postage U.S. funds 

N.J Residents add b% Sales Tax. Money Back Guarantee 




MA1003 MOBILE CLOCK 

MODULE (National) 
$21,95 complete 



Attaches directly to Automatic Kighttime 

9-12V Buttery Dimming 

Fluorescent Display gives Color Ctioice 

(Red, Blue, Green or Yellow; 

^■f>en used w/coriesponLling Colcr Filter 

Includes — Module, S*,:ciEi. Filter a Soecs 



i^ 



PAIR OF 6" PIONEER *^!* 

PINCUSHION SPEAKERS 

32 ohms. 71 ivj-ts .. .. S395 pa' 

Pair of 4" Full Range Speakers 

't (J ohms . 52 95 oair 

AC/DC WALL PLUG ADAPTOR-CHARGER 

120 uolt input/6 VDC 130MA output $1.00 

£ RPH Gear Motor Syn. Timer Type S? 95 



VOLTAGE REGULATORS 



Posilive-To 220 Pkg. 

7805 Sl.OO 

7806 . 1.00 

7812 1.00 

7315 l.CO 

7S2i ... .. i.OO 



Nejative.To 220 Pkj- 



7905 
7912 
7915 

t.^^309K 



T0.3 Ptg. 



$1,25 
1,25 
125 

IS 



7 SEG LEO DISPUYS 

33" Type 707/MAN 1 14 Pin Dip 
Common An node or Cathode 



$.59 ea. . 

CLOCK CHIPS 

MM5314 53 50 

MM5316 350 

f^M5387 |Hi C-jf53!6) 3.95 

MM5375 3 95 

BRIDGES 

r..Anio200voU . 3/1.00 

6 Amp 600 vol; . 3/2.00 

25 Amp 2CC rolls 3/5 CO 

2 S Amp ICCG vo't 5/j CO 



to lor S5.00 

TRANSFORMERS 

P:ue type 12i'AC 250MA 2 50 
PC Mn-L-]2VJC 250WA 1.50 
Bil ,Mnl..5VAC6Amti i.Si 



IC SOCKETS 

8,14.16,18 Pin , 5 lor 1,00 
24PinA2SP'n 3 lor 100 
40 Pn .2 lor l.CO 



lED's 

lumbo Red LED's 

25 Pk LED's Assld. Sizes t, Colors 
Bi.Polar LED Reri/Green 



10 (or I.OO 



100 for 9.00 

2.50 

1.00 



LED Kit - a $4.00 Value - $2.50 

Includes: • 1— Bipolar Red/Green 

• 1— Hi Intensity • 3— Gfeftn. Jumbo 

• 12— Red Assorted • ?— Yetlow, Jumbo 

• 1 — Panef Mounts 



SWITCHES 




Pushbutton. Mon On 


.3 lor l.SC 


Mini Toejlc-SPDI 


... 125 


Minilncgle-SPm 




On.Cenltr Dff.Hon On 


125 


Vim lr,',j!.!)PDT 


153 


Rozif. ;,PE-T 


5 ^or 1 m 


Rn;i=i !1FD: 


5 !or 1 :G 



WOOD CLOCK 
CABINETS 

includes: filter & Back 

Walnot (5rain or 
Slack Leaiheretle Finish 

$5.00 ea. 

Dimensions (Inside] 

■A — 1.13/16"H, 5'j"W 4':"D- 

B - l':"H, 4'/W, 4':'D 

Entra filters-)- Red, Smcke 

Blue. Amber, £ Greer — S.GO 



Dual Range DVM/Hultimeter Kit 

DVM Kit only - - S29,95 complete 

Multimeter Kii inci Power Supply $44.95 complote 

features: to + .2, • 2 eio. up to ♦ 200 volts DC 

• Intersil CMOS Cfrip Sel • .Accuracy to within .001 

• High HoiSfi Rejection • Non Critical Components 
Contains: PC Boards, large ,50 fairchild Readouts 

All components, switches, comptete Insts. 
A Specs 



$9.95 

Complete Clock Kit 

4 DIGIT 12/24 HOUR 



^ 



Includes: PC Baart: 5316 Ciock Chip, all co'^Dorents £ 

Power Supply 
Features: DispJays hrs & mjn ■ Switch lo fflin & seconds 
• AM/PM ^ndic3tor • [lapsed Tsmer 
» Ffirorescent Dispiay gives color choice 
[Red, Bfue. Gfeen. or Amber) - specify 
/.■hen Lsd with cDrr&spj^-Ctrfi Cocf Fiiter 
OPTIONS: l! a;.3.-m Furclion tJ^s-eJ sJd - - 

PfeiFt'3£ Case K:-[ ■ Rea .■' 3- -? . 



S2.5D 
52 00 



60 Hz. Crystal Time Base Kit 
S4.95 

Use with Diiilal Clacts lor IZVDC 01 Portable Operation 
KIT INCLUDES: 

PC Board, 5369 Divider Chip 

3.5795 MH2 XTAL & All Other Parts 

Complete instructions 



Blinky/Flasher/Timing Kit 
$2.50 each SfofSlO.OO 



Kit includes: 



<#* 



P.C. Board. 555 fimei. aH cornpomsnts 
and a correciof for s 9V Battery 



6 Digit LED Stop-Watch Kit 
$29.95 complete a 



# 



X 



FEATUSfS: ?.::'.65 iinules s^:oncis J lOOliis o' seronas 

b :::^ht .asiiy 'eadaoie digits 

Needs wily one S volt Xistor tjattery 
KIT IHCLtJOES: • -lar-n' ■-■?« il<i Otsignec lor iiircve 

• Latest Technoluiiy Intersil Mos€,"iip « 7205 
. « 32768 MH! Ciystdi • Variable rrimmer Cap 

• 2 mrni slide S, 3 t^OI^. PG Sv^itches 

• 3 parrs (6 dierisl Double Dioit LEO Qisnlays 
P.C BOABDtorstMve 



6 DIGIT LED MOBILE 

Clock Kit & Elapsed Timer 




..4" Digits 12 or 24 Hr 
Quarti Crysia! Controlled 
i; Volt DC or AC oppialion 

$27,95 Ccn'piete 

(less 9V batleryj 



I Protection fron] noise 

a HiRh Impulses 
^ C \d^v Slanhn^t Capabi.^ 
► Bilteif Gack-U'; ■^.iratj ily 



•Sue 4" I 1'.' > IV 
•SuggEd H.ji l-oacfABS 
* Recessed Fr,-nt Swtthes 



OPTION - AC Adaptor $2,50 



BIG-BRIGHT - ,5" LED ALARM CLOCK 

e DIGIT AC or DC or ELAPSED TIMED KIT 

$19,95 Complete 

• PC Board Drilled S Silk Screened (Includes Xlai Time Base 
Circtiitryl 

• 5375 Nat. Clock Chip & Faiictiild Displays 

• Irrriudes EVERY psi' requiied lor r-tJ^k and ^11 options except 
Cabn.-: and Crystal " -e Base CGm.pulieiils I desirec, see t)e!D« 

• Brighlress Cori^r^l •» J- Hr Alarm w/siliioie 

• Freeze "-i-al on eweiy mode " 0-60 Min. Elain^^d Timer 

• Field Tisti'i c»ei If-. • 12 rii 6C H; ooei 

Most Important — Complete Instructions, schematics Pictorials, 

layouts ~ everything (or troutile Iree assembly. 

OPTIONS - 
XTAL Time Base Components . $2.95 when purchased w/clock 
Wood Clock Cabinei - S4 00 when purchased w/clDr;k 

12/24 Hr. Version of Above si795 

except no Alarm or Elapsed Timer 



H23 



190 



master charge 



MICROCOMPUTER 



gOBOA 

SUPPORT DEVICES 



8212 
8214 
8216 
8224 
8228 
8238 
8251 
S253 
8255 
8257 
8259 
6800 SUPPORT 



681 OP 

6820P 

6828P 

6834P 

6850P 

68S2P 

6860P 

6862P 

6880P 

Z80 

SUPPORT DEVICES 

3881 15.95 

3382 15.95 

F-8 SUPPORT DEVICES 



4.00 

12.95 

5.25 

6.00 

9.25 

8.20 

12.00 

28.00 

12.00 

22.00 

22.00 

6.00 

8.O0 

9.60 

21.95 

12.00 

17.00 

15.00 

18.00 

2.70 



3851 
3852 



14.95 
14.95 



FLOPPY 

DISC CONTROLLER 



PD372D 
1771 



65.00 
69.95 



DYNAMIC RAM S 

414D (16P) 
1103 (16P) 
2104 (16P) 
2107B {22P) 
2107B-4 (22P) 
TMS4050 (18P) 
TMS4060 (22P) 
4096 (16P) 
IVIM5262 (22P) 
IV1M5270 (18P) 
MM5280 (22P) 



5,50 
1.50 
6.S0 
4.50 
4.00 
4.50 
4.50 
5.50 
3.00 
5.00 
6.00 



STATIC RAMS 

31L01 

91LriA 

91L12A 

1101A 

2101 

2102 dOSl 

2102-1 (S.OONS) 

2M1A-4 

2112A-4 

25016 

3107 
*4200A (250NS) 

410D {20aNS) 
*4804 

5101 

74C89 

74S201 

91L02A 

7489 

8225 

8599 

82S09 
*Limited supply. 



2.00 
4.25 
4.25 
1.00 
3.00 
1.25 
1.50 
4.45 
3.00 
1.45 
2.95 
13.75 
11.95 
20.00 
20.00 
3.00 
4.75 
2.00 
2.25 
1.50 
1.50 
9.00 



MISC OTHER 
COMPONENTS 

N H0025CN 

NH0026CM 

N8T20 

NB26 

N8T97 

74367 

DM8098 

1488 

1489 

3205 

D-3207A 

C-3404 

P-340BA 

P-4201 

MM-5320 

MM-5369 

DM-8130 

DIVI-8131 

DM-8831 

DM-8833 

DM-8835 

SK74LS367 

SN74LS368 



1.75 
3.00 
4.00 
3.25 
1.45 
1.00 
1.00 
1.95 
1.95 
6.20 
2.50 
3.95 
6.75 
4.95 
7.50 
2.00 
3.00 
2.50 
2.50 
2.50 
2.50 
1.00 
1.00 



MICROPROCESSORS 



F-8 

Z-80 

Z-80A 

CDP1802DC 

AM2901 

6502 

6800 

8008 1 

8080A 

8080B 



19.95 
36.95 
49.95 
29.50 
22.95 
24.95 
24.95 
8.75 
15.95 
16.95 



SHIFT REGISTERS 
DYNAMIC 



1404 AN 3.00 

2405 4.95 

2505K 3.00 

SHIFT REGISTERS 
STATIC 



WIIV!506 

2509K 

2518B 

2533V 

TMS3002 

TMS3112 

MM5058 



.89 
1.00 
3.95 
2.00 
1.00 
3.95 
2.00 



FIFO 

3341 A 
2812-D 



6.75 
11.95 



KEYBOARD CHIPS 

AY5-2376 14.95 

AY5-3600 1 4.95 

TV GAME CHIPS 

TMS1955(6Games| 

10.95 

AYSS-8500 16 Games) 

10.95 



USRT 

S-2350 
IM-6403 
TMS-6011 (Tl) 
TR-1602A (WD) 

U A RTS 

AY5-1013 
AY5-1014A 




6.75 
9.95 



CHARACTER 
GENERATORS 

2513 

2513 

3257 

MCM6571 

MCM6571A 

MCIVI6572 

MCM6581 



WAVEFORM 
GENERATOR 

8038 

MC4024 

566 



6.75 
6.75 
18.00 
10.80 
10.80 
10.80 
8.75 



4.50 
2.75 
2.00 



PROM'S 



1702A 

1702AL 

2704 

2708 

2716 

3601 

5203AQ 



■5.00 

7.00 

20.00 

24.00 

75,00 

4.50 

7.00 



5204AQ 

6834 

6834-1 

82S23B 

82S129B 

8223B 



10.00 
21.95 
16,95 
4.00 
4.25 
4.00 



IMSAI/ ALTAI R 



S-100 



COMPATIBLE 



jadeZSO 

KIT 

—With PROVISIONS for 

ONBOARD 2708 and POWER ON JUMP 

$135.00 EA. 




Electronics for the Hobbyist and Experimenter 



S351 WEST 144th STREET 

LAWNDALE, CALIFORNIA 90260 

1213) 679-3313 



Discounts available at OEM quantities, Add $1 .25 
for shipping. California residents add 6% sales tax. 



Assembled & Tested 



8K STATIC RAM BOARD 

250ns. S209.95 

350ns. |1 9a95 

450ns. $189.95 

* WILL WORK WITH NO FRONT PA"NEL 
^ FULL DOCUMENTATION 

* FULLY BUFFERED 

* S100 DESIGN 

* ADEQUATELY BYPASSED 

* LOW POWER SCHOTTKY SUPPORT IC'S 



KIT 



250ns. 
350ns. 
450IIS. 



$169.95 
149.95 
;i 39.95 



J6 



191 



AAAAAAAAAAAAAAAA AAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAA 



HEW il ELECTRONIC TOUCH ORGAN KIT 




"Ideal kit 



Fantasiic new desrgn uses CMOS I.C. and a to- 
tal of 39 semi-conductors to give a touch con- 
trol keytioard, all the eJectronic parts in one PC 
Board. This organ ss sasy to build, yet has fea 
tu^es like a full tx.'vo-octave range touch key- 
boarci, variaole tremolo; two voices; built in LC. 
amplifier with volume control, compfele -A'ith 
speaker arid 3 speciallv designed ple>ti-glass 
case, 
for i>e9tnner or gift for children >2h«50 GO* 




Model 250-30A 



30MHZ FREQUENCY COUNTER KIT 

Take adwaniage of this new state af-lhe-nn counter leai:uj-ing rne many bwrefits of custom 
LSI circuitrv. This new technaloqy approach to insToimeniation yields enhanced p^rfor- 
mancB, smdier phY^ital sfzc, tirjsticslly reduced power consumrition (pcrT^ble battel^ 
operation is now practical], dependahilily, easy assembly and fKwoluiionarv lower pricing! 
' 0.5" red LED 6 digits display 
' Resolution: 1 Hz at 1 sec. lO Hz 3t 1/10 sec. 
■ Scnsiiivitv: ID Mv RMS to 30 H/ 
' Jnternal po^/ver supply; E.2V at 1 omia regulated 
Includes all parts. ' Irrput coritiGctor; BMC typa 

PC Board and TranSforrner * Iriput power required; 1 17V AC RO/SO I-):; 



Onis, $59.S0 



CALCULATOR 

with STOPWATCH 

6 Functions witti % and mfcmory 

8 Digits big green display 

'Built-in X'tal controlled stop 

watch count to I.'IO o-? a second. 

Special Price Only 

$16.50 Ea. 

BATTEFHE5 NOT lrjt(_Uf)ED 





IWoU AUDIO AMP 

All parts are pre assembled 

on d mini PC Eoerd 

Supply Votlage 6 — 3V D.C. 

SPECrAL PR ICE SI .95 ea. 



•*:< 




2W+ 2W STEREO AMP 



J UWatO !.C_. waiun-,^!, 
KJ., Ir^jtilp- gqntfDp rnc! aded 

.ZT.\v vt>itaric g 15V D.C. 
iTijiTv lOOVv for full ojiuu 
rnT.il fiarmonir; riiitarnon. 
l-i :™ 1 <H; '^ 1 5 .vaiT 

ONLY $5.75 ea. 




SW AUDIO AMP KIT 



2 \M 330 wiih Votume Con 
PoiV'jr Rlii^dIv G~1BV DC 

only *5.00e«». 



^i 




TIMER KIT 

Time ControUed Jrom 1-100sec. 
-t^; :-,. .■■ .jsed 25 Time ti.-. jy 

serviiia. ni'iri other !Ji.-rp05C£ 

^^a^<. 'Dadin^ nov, 2 amp 

;t..|i|-lv voUace 1? 13V DC 

; T.i^th Sn.50 each 



ELECTRONIC ALARM SIREN 

COMPLETE UMT 
Of r;:o-. j;: IS vO-j f car r;s.< LR" 
^^g .'^ii-t rp.iaLi LT. TO 130 uG 




19 KET HEXADECIMAL 
KEY PAD 

* 1 —0 ■ Homekey 

* ABCDEF *<-^Key 

SPECIAL $10,50 63. 

Low Cost Hexadecimal 16 Key Pad 



■ ('■-siHiJ fDrComuLitei 

ilry Part aT Digital Lo^ 

,rll Ipeling S0.95 8 



DICITAL ELECTRONIC LOCK KIT 



floon. '^Ei.yiv J 



no hev pad JSOT I 







POWER SUPPLY KIT 

a-30V D.C. REGULATED 
U5e5 UA723 and i^NSOsS Pov.-^r 
TR Outpjt can be adjusted Irom 
3DU, 5 AMP. ComDlete t'Jtih PC 
board and 3II electronic par-ts, 

.-« PPWK^ ^L.-Fi.T S9.50 each 



IV1A1003, 12V DC CLOCK MODULE 

luilt in X'TAL conTrolled 
time base. Protected against 
autOfnotive volt transients. 
Automatic brightness con- 
trol with 0.3" green color 
display. Display turnoff 
£19 50 with ignition "OFF". 




LCD DICITAL THERMOMETER 




Dt>sk Top ModeJ 
66*^ - Be° F 



Only $375 each 



\ 



QUARTZ CRYSTALS 

2 r/HZ SB 5a 

10 h*HZ ^^ I'l 

Celo^ TV -y-r 



0* 



.«P CB MICROPHONE 



C? 



500 MIC force Unit 

Talk Sw[Tch iiviTh 

Connector and Cord 

$2.50 each/3 for $5.00 

CLOSE OUT SALE 



TV CAME MODULATOR UNIT 

FCC Appfo-ed 



ONLY S4.50 

Tl 1355 

7V G^'-^^e Cl-,p .-.in :^.iTa 




Special Only SE.SO 



/I RECHARGEABLE 

/P 



u 



BATTERIES 

AA SIZE. 1 .2V S1.25 ^a. 

CSIZE, 1.2V S1.50 ea. 

SUB C SIZE 31.50 ea. 

F SIZE, 1.2V S2.50 03. 

5 SUB C dV PAC< S4.90 ea. 



BATTERY HOLDERS 



O.ao 1 

0.30 i 

0.35 ! 

0,50 t 

0.50 i 



ON-SCRfiN TV 
CLOCK KIT 

Same one as in July Radio 
E letiironlcs. K it includes PC 
Board, MM531S and MM5841 
chip. All other electronic parts 
tfvith trgnsformer. 

ONLY $21,00 



BIPOLAR LEO 

Jumbo Size red''green c'^ang^ color 
^vhcn revej"sc polarity ol" vohii-qG 
iflOai far Cja/nogo ifidicaiOr. ^ 

Two for S^ ,00 ~tw~' 



!.C. TEST CLIPS 



&3rns as vho E Z r 1 
-I bla = k sr--;J =e'j ^o 

S3.7S per pail 




ELECTRONIC 
SWITCH KIT 

CONDENSER TYPE 

Touch on Touch Off 

use 7473 1 C 

and 12V falay 

S5.50 each 






SOUND ACTIVATED SWITCH 




► 



Sub-Mini Size 

Condenser Microphone 

$2.50 eadi 

FET Tranji^tor Bullt-ln 



SIGMA 78HEI, 12DC RELAY 

4D0n COIL SPOT 

SI. 30 ea. or 10 for $10.00 

ALL BRAND NEW UNITS 




COMPUTER GRADE CAPACITORS 

5.SC0 uFaeav s?ra.-- 



P^ 



D 



'0,000 ^'FD^Ov S:i jS n 

1 1.5D0 ^/FD 75V 33.*)^. <■ 

3d,SK) VPD50V SJ.2ir 

39,000 VFD 12V S2 00 (■ 

100.000 ^':i^0 6v Si.-[^c 



TV Gomes 




S*f«B Only 

S19.S0 



nATUHSt 

■ -1 Games-Termre. Ho 
R^couet Handball ana 
q\e Handbaii. 

• Auto counter cisplav c 



WIRE 

WRAPPING 

TOOL 

$29.50 

Wire Wrapping 

In Bulk 
100' $2.00 

500' SS.50 




J3i 



Sub Mir>i S^ze 
1^ PAMELMETeR- 
600 UA 
ONLY SI. 20 ea 



-=^, 




POWER TRANSISTOflS 



S2.25PfP: PAIR 



^ TRANSFORMERS 

All 117 VCLT IMf'JT 



30V 3[ TE /..Tirt S3a on ...^ 

:16V CT at 3 amp 5 4 V.U ua 

jGV CTa; 2 5,im|i S 4,50 (?j 

■^av CT at 2-5amp S 4/jOo«. 

i:?V(^t2a\y a: 2 ai-np S 3-9 *a 

24V CT at 800MA S IBOnji 

0.3 V 12V at 400MA ^ 1.8 CD 

AC POWEI SUPPLY 

AoapTar Tvpa Tran^tormBr 
13V ACOutput 200 MA 
$2.75 such 
6V DC Output 13QMA S1.90««, 
8.7VDC Output 130MA S1,90m. 
12V DC Output 100MA S1.90.S, 



IBDUAIVIETER. 

only J. " ■ I 

51.50 ea. -■^'^^■1 



SO UA PANEL METER 




CLOCK KIT 

\ MOST POPULAR 

MM5314 KIT 



► 




Special Onltj $M,95ea. 



MINI-SIZED I.C. 
AM RADIO 

iize smaller than a hox of iTiflithegi] 

Receives all Alvl sratfun^ 
Batteries and ear phons includeci 



Only $8.50 










fP^^ 



^*^ TOGGLE SWITCH 



-'-^1 't^il 1?!^V RCcnni^r 

1 J..'in ?? 
2i^ ^:^ 7- I (i.-i .! ic 



SU8 MINIATURES TOCCLE 
SWITCHES 



d A 



► 




JO V STICK 

C '00^ yDl,.n.i,- pq 



PUSH-BUTTON SWITCH 

:^ff^ Greer, Black. 4/tI.OO 

^WP Avei!3E3l!? 50c ca. 



-► 



SOLID STATE ELECTflOBIC auZitK 









F6 



$% FORMULA INTERNATIONAL INC. 

STORE HOURS iQ^IV^nndny Sjt"f(i,Jv 



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1§2 



TRICO TRICO TRICO TRICO TRICO TR1CO TRICO TRICO TRICO TRICO TRICO TRtCO TRICO TRICO TRICO 



30 MHZ LOW COST FREQUENCY COUNTER KIT 



Features: 

* Frequency Range— 100Hz to 30 Hz min., resolution 100 Hz 

* All TT L Circuitry— No tears in the eyes vyhen replacing ICs 

* PET Input Stage— Offers high input impedance 

* High Sensitivity- tBrnV typical 
■ Xytal Time Base— 1 OMHz for better accuracy 

* On Board Regulator— No external power supply needed 
' All ICs Socketed— Easy to service 

* Easy to Operate— No switches to flip 

* Tin Plated Si Screened Board— For easy assembly 

KIT INCLUDES: Detailed Instructions (22 pages). All parts Including transformer (case not 




available). 



COMPARE 

and 
SAVE! 



$54 



99 



ET-ZS0-30A 



PUT YOUR HAM GEAR OR CB IN YOUR HOUSE WITH THIS SPECIALLY DESIGNED POWER SUPPLY KIT! 

A lot of companies offered you this kind of power supply with very poor quality. Either the ripple is too high or the output voltage 
is not stable. Some of them even made their power supply with a sener diode and a resistor! Nobody has ever considered the safety 
of your equipment. With our kit, you can be sure of high quality and your equipment is protected against any failure of your power 
supply by a built in OVP circuit. 

KIT INCLtJDES; Transformer, PC Board, Large heat sink, Large filtering ONLY $16 95 



capacitor and all the parts with detailed instruction. 



WOW ! LOOK AT THIS ! 

5V lOA Power Supply Kit for your 
TTL Circuits! 

Kit Includes: ExUa Large Heat Sink. Pow- 
er Tr., IC Regulator. P. C. Board, v»plh OVP 
Crcunrv. „„ :a »..™ $11.95 



Kit ** T-&00 

Wiih Optional ^fru ii i i u i. Rectifiers and 

Filtering Capacitor, $14.95 




(X'former not available) 



6-DIGIT AUTO CLOCK KIT WITH ALARM 



Feature$: 

A. FairchilfiO.5"' FIMD 500 

Series Oisplav 
8. Display Board mav be 

remote 



C- X'lal tfms base 

D. P.C. Boards, speaker, IC's a-** «■- 
and all parts. $19.95 

E. Detailed Instructions kjt # t-iso: 



HERE'S A MUST FOR THE EXPERIMENTER! 




2-20\/ @ 1 .3A Continuously Variable Pow- 
er Supply Kit. Kir Includes; P.C. Board, 
TrarisJormer, Pawer Transistor, Heat Sink, 
IC Regulator & ati the parts with detailed 
instruction. C;i'5 QC 

KIT # T-63E i& IZ.99 



This 



0.8" 4 Digit Jumbo Display Alarm Clock Kit 

Features: 

A. Fairchild 0.8" FSC8000 Display Array /\ 

B. Fairchild Super-Chip - F-3817PC 

C. P.C. Board, Transformer, Speaker and all 

parts included (less case) Sl9 50 

D. Detailed Instructions 



Big 



IS 

Ot\l^, 



MINIATURE SLIDE SWITCH 

DPDT .20 each 

10 for $1.75 

100 for $16.00 



PUSH BUTTON SWITCH 

Red, White, green and 
yellow 30*83. 4/$1.00 



PANEL METERS 



50mA 
100mA 



214" X 2%" 
$3.00 150mA 
$3.00 300mA-. 



$3.00 
$3.00 



3" GIANT SOLAR CELLS 

The largest, most powerful solar cells 

awaHatile. 0.9amp (e> 0.45V. Can be 

ganged for higher voltage or current. 

Special for just $7.95 ea. 

10 for $69.95 




POWER TRANSISTORS 

MATCHED PAIR 

MOTOROLA MJe2955 PNP 

lViJE3055 NPN' 

10 AMP 60 VOLT 90 WATTS 

$225 PER PAIR 






MULTI-COLOR LED INDICATOR 

Red— Green Colors in one L£0 

with Plaslfc Housing 

g9cEa. 

Voltaoe 2V 20 WA per LED 



MINIATURE TOGGLE SWITCH 

SPOT On-Off S1.30ea. 
DPDT On-Off SI .50 ea. 
•■iSi^Si- 3PDT On-Off $1.75ea. 
'^^^'^ Wlini-Size Rocker Type 

also available at the same price 



■ - 'HE 



CLOCK CHIPS 

JV1M5376AA S4.25 IV1M5375AE S4.25 



60 Hz Time Base IC MiVI5369 $1.95 



TRANSISTORS 

NPN-General Purpose 30V 10/$1.00 
PNP General Purpose 30V 10/S1.00 
2N2222 -Switching 10/$1..50 

2N3055-150W Power 10/$6.75 

2N6059-Darllngton Power, $3.25 ea. 
20A HFE Ik Typical 



WIRE-WRAP TOOLS from OK 
Hobby Wrap 30 $5.45 

Hobby Wrap-Model BW-630 Bat- 
tarv.pp. (less batt.) $30.95 



PLASTIC PUSH BUTTON SWITCH 

J-188-1 Push On — Push Off 

J-1S8-3 Normallv Closed 

J-188-2 Normally Open 

45c or 10/$4.00 



OPEN f=RAME POWER SUPPLY 

5V (£> 3A with OVP 1 1 5V AC 
input $17.50 



CPU S080A 

ONLY $16^5 

Special from Tl 

2716 - tSK EROM 

ONLY $39.95 



CRYSTALS 

1MHz $4.50 

4MHz $4.50 

lOMHz $4.50 



. _ LED's 

Q.20" Red 25« 10for$1.75 
0.20" Green 30* 10 for $2.50 
0.125" Red 20e 10 lor $1.75 
0.5" FND503C.C. $1.00 

0.5" FND507 C.A. $1.00 

0.3" FSC8000 C.C. $5.00 



INTER-COM BOARD 

Fullv assembled. 

Works on 9^15V D.C. 

2 speakers make it work. 

With Schematic 

ONLYS3.00 



TANTALUM 
CAPACITORS 

ItiZS'i/ .15 

IpilOV 
3.3H35V 
10/J50V 
22iJ 35V 



COMPUTER GRADE 
CAPACITORS 



.15 
.20 
.35 
.25 



6,000 JUF 
10,000 )MF 
27,000 fdf 
30,000 jUF 
36,000 HF 
63,000 jUF 
100,000 ^F 



75V 
60V 
50V 
15V 
30 V 
15V 
5V 



4,50 
4.25 
4.50 
3.50 
4.00 
3.95 
2.00 



BOURMSTRIMPOT 

ComfTiBrcial Single Turn 2K 3305P 

ST.25aa. 10«10J0 

Cerrael Mil. Spec. Muhl.rurti IK S 2K RJ2<5CX 

$3.00 aa. 10/S25.00 



PRIME FROM ERIE 

10-40p Mini Capacitance Trimmer 
75(!:ea, 10/S5.00 




AN2144.SW Power IC with spec. Supply uoltage = 13V $2.95 ea. 
MH0026-5iVlHi Clock Driver $1 .95 ea, 

6V 1 30mA A/C Adaptor/charger $1 .25 ea. 

0.2" - Red Fairchild L.E.D. 100/$10.00 

14-pin Lo pro IC Socket 100/$16.00 

16-ptn Lo pro IC Socket 100/$17.00 



03IU1 03IU1 OOiUl 03IU1 03IU1 OOIUI OOIUI 03IUJ. 03IU1 OOmi OOIUI 03lbi 



/j 



TEftMS: Money Back Gitar^ntes 

CALIK. RESIDENTS ADD 6^ SAL.^^ TAX 

Ples&e add$1.00 fo/ postage TntLcle Cajff,, S2,Q0 for 

Oul ot Slaie, Overseas add 10% oi or^fj. || 

Minimum Omer SS.OO CO.D. SIO.OO ISl ,00 handlinsJ 
STORE HOURS: Mon.Sal., 10-7 

PHONE 7t4/SZ1-0Z34 



T21 



ELECTRONIC SUPPLIES 

Please send your checK or money order to: 

P.O. Sox 420B, Anaheim, Ca. 92803 

Visit our new location it: 

Z795 W. Lincoln Ave., Suite L, Anaheim, Ca. 92BOT 



EVER WISH YOUR RECEIVER 
COULD HEAR THE WEAK ONES? 

Almost every amateur and commercial 
VHF/UHF receiver can be more sensitive 
with these popular preamps. Ovef 7000 
in use throughout the A-orld' 



FWI/CW TRANSMITTER KITS 



VHF/UHF m RCVR KITS 



P8 KIT $7.95 



Pli W/T 16-95 



Recommended for moLntmg inside ^.-o^5celve^s 
— " only 1/2 X 2^3/8 Inches 



■IMi^ 



MODEL 
P8-30 
P8-150 
P8-220 
V-]6 (W/T) 



RANGE 
20-83MHZ 
83-190 MHz 
220-230 MHz 
Give exoch freq . 



P9 KIT $9.95 



P14 W/T 519.95 



Premium model where ipace permlfs — 
1-1/2x3 inches. Ideol for OSCAR! 




MODEL 
P9-30 
P9-!50 
P9-220 
PI4 (W/T) 



R AN GE 
26-88 MHz 
88-172 MHz 
172-230 MHi 
Give exact freq. 



PIS KIT $15.95 
P35 W/T 534.95 



i AvoMable for 

any band 

380-520 MHz 
t 20 dB gain 



k; 







VHF AND UHF CONVERTERS 



• Low noise F5T 
front end 

m Al I common i-f '; 

< Great for OSCAR! <, 

• Low power drain 

• Crystals ovolloble 
for any desired freq scheme 

MODEL C25 VHF CONVERTER KIT (shown) 

J2S.95 

• Models for 2M, 6M, lOM, 220 MHz, air- 
croft, cam'l, etc. • Stable coscode rf stage 

• 0.3-0.5 uV sensitivity • 10-20 dBgain 

• Compact 2-1/2 X 4-1/2" pcb • Any i-f 
10-50 MHz • Featured in HR mog orticle 

MODEL U20-450 UHF CONVERTER $19.95 

• For 432-4^5 MHz ssb, otv, OSCAR, 450 
MiHz Fti, oircrcft, com'3, etc, « Economy 
converter * Use with P15 PreCTip for optJnum 
performance • Any i-f 10-160 MHz 

XTAL (either of above) 




200 MW EXCITER MODULE KITS 

T40-n Eleven Channel Exciter for 2M, 

6M, or 220 MHz 539,95 

T40-1 One Channel Exciter 34.95 



T20 Tripler/Driver Module Kit, 150 mW 
2M input, 200 mW 450 MHz output $19.95 




RF POWER AMPLIFIER MODULES 

■ NO TUNING .VSWR PROTECTED 

> 150 MV'/ DRIVE • COMPLETELY STABLE 

T8Q-T50, 140-175 MHz, 20-25W output, 
wired ond tested, simply connect yoiJr 
cables $79.95 

T80-450, 43G-470 MHz, 13-1 5W 79.95 



TEST PROBE KITS 



ONLY $7.95/ea. 



TE-3 RF Defector Probe For VTVM, good 

from 100 kHz to over 500 MHz 
TE~4 Direcl- Probe for ac/ohm^^ etc. 
TE-5 DC Probe w/res for 11 mtg Inpuf VTVM 
TE-6 Blockmg Capacitor Probe T^or counter, 

signal generator, etc. 
TE-7 VVJdebcnc Detecl-or Probe for scopes 
Tt^S Hlgli Z/ Low CopociJcoce ^cope probe 



(fO)) 

'^Lorsen flntennos 

We have o large stock of these popular whips. 
Pick the mount ond whip which are right for 
yau! All whips and mounts are interchange- 
able. Request catalog for more information. 

LM-150 5/8 wave 2meter whip $23.85 

LM-220 5/8 wave 220 MHz whip.,, 23.85 

LM-440 Colineor 450 MHz whip 23.85 

Q 1/4 wove whip 144-450 MHz 2.65 

MM-LM-K Mognet Mount S14.60 

LM-K 3/4" Blind Hole Mount., 6.35 

GC-LM-K Gutter Clip Mount 14.60 

TLM-LM-K Trunk Lip Mount 14.05 

AMD-K Trunk Gutter Mount 9,10 





VHF MODELS FORJVNY BAND 28-240 MHz 

R60-( ), 0.5-1 uV sens, incS VHF Converter 
ond IF/ Audio Boards S64.95 

R69-( ), 0.2-0.4 uV sens, inci P9 Praamp, 
VHF Converter, and IE/Audio ... S69.95 

Crystals (We stock common freq and will 
gladly order specials) S5.50 




UHFMODELS FOR ANY BAND 380-520 MHz 

R60-450, 5-10 uV economy rcvr, IncI UHF 
Conv 6 IF/Audio Boards only. .. . S59.95 

S80-450, 2-5 uV sens monitor rcvr, JncI UKF 
Conv, VHF Conv, and IF/Audio . S84.95 

R95-450, 0.4-1 uV sens rcvr, incl P15 Pre- 
oir.p, UHF Conv, VHF Conv, and !F-Audio 
Boards S94.95 



TTfi 



mn 



F AMiOUS 
ANTENNAS 
STOCKED IN DEPTH 



REQUEST CATALOG FOR MORE DETAILS 



14AVQ 

18AVT 

18HT 

TH3-MK3 

TH3-JR 

TH6-DXX 

2BDQ 

5BDQ 

263 ' .. 

265 

214 



10-40M Vertical 
10-BOM Vertical 
1 0-SOM Hy-Tower Vert 
Tribander ^ ' - 

Trilxinder 

Tribander, 6 element 
80-40M Trap Dipole 
80-iOM Trap Dipole 
.2U\ 5/^ wave Trunk Lip 
2M 5/S wave Mag Mt 
14 el 2jVi Beam 



$67.00 
97.00 
279.95 
199.95 
144.50 
249,95 
49.95 
79.95 
23.95 
29.95 
26.95 




SUPERIOR 
QUALITY- 
Yet only $189.95 



IF YOU'VE HEARD THE NEW 
HY-GAIN 2M HT, YOU ALREADY 
KNOW IT'S FANTASTIC I WE 
HAVE THEM IN STOCK COMPLETE 
WITH CRYSTALS AND ACCY'S 



Inexpensive DC POWER SUPPLIES 



Model 


Price 


Intermittent 


Cart 


12C&4 


$29.95 


2.5A 


l.SA 


1Q3R 


39.95 


4A 


2.5A 


104R 


49.95 


6A 


4A 


108RA 


79.95 


12A 


8A 


I08RM' 


99.95 


12A 


8A 


109R' 


149.95 


25A 


lOA 



"Indicates model wtiich has panel meler<s) 



CALL OR WRITE NOW FOR FREE CATALOG OR 

TO PLACE YOUR ORDER! 

PHONE 71fi-663-9254, 9AM-9PtVl EST DAILY. 

Use your credit card or C.O.O. 

Specify opafatifig freq • Add $1 shipping ajid handling. 



194 



r'l^Bwww** 



GET YOUR 



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RADIO AMATEUR 





CALLBOOKS 



The U.S. Callbook has over 
300,000 W & K listings. t1 lists 
calls, license classes, names 
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PLUS SHIPPING 



Specialize in DX? Then you're 
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dealer or write direct for free 
catalog to the publisher. 




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ca 



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llbook 



INC. 

Dept. B 925 Sherwood Drive 
Like Bluff. III. 60044 



ALL OF THESE EXTRA FEATURES INCLUDED 



International Radio Amateur Prefixes! 

Radio Amateur Prefixes by Countries! 

A,R R L, Phonetic Alphabet! 

Great Circle Bearings and Charts 

International "Q" and "Z" Signals! 

World Standard Time Charts! 

International Postal Information 

World Prefix Map! 

F.C-C. Examination Points! 

Where to Buy! 

Telegraphers' Abbreviations! 

DX Operating Code!- 

A.B.R.L. Countries List! 

At Your Service — Amateur Radio Dealers! 

QSL rvlanagefs Around the World! 

World wide QSL Bureaus! 

Census of Radio Amateurs of the World! 

Telegraph Codes! 

AMSAT — Oscar Users Directory! ,,. 

Slov^ Scan Television Directory! 

Reciprocal Licenses! 

Hawaii Included! 

Many Other Features! 



Respected worldwide as 
the only complete authority 
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QSL and QJH information. 



Save $1.50,order both, send $30.40 



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City 



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Charge ; O BankAjnexiicaid 



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a Master Ctiarfie Interbank # . 



Credit card #_ 
S ign ature , — 



Expiration date^ 



R1 



195 



THE FUTURE NOW! ^SSSiUt^mZ 

All Solid State CMOS PLL digital synthesized - No Crystals to buy! 5KHz steps - 
144-149 MHz-LED digital readout PLUS MARS-CAP.* 

• 5MHzBand Coverage - 1 000 Channels (instead of the usual 2MHz to 4M Hz -400 
to 800 Channels). 4 CHANNEL RAM (C MEMORY WITH SCANNING-MULTIPLE 
FREQUENCY OFFSETS - Electronic Auto Tuning, Transmit and Receive-internal 
Multipurpose Tone Oscilator-RIT-Discriminator Meter #15 Watts Output - • 
Unequaled Receiver Sensitivity and Selectivity-15 Pole Filter-Monolithic Crystal 
Filter and Automatic Tuned Receiver Front End-COMPARE! • Superb Engineering 
and Superior Commercial Avionics Grade Quality and Construction Second to 
None at ANY PRICE. 



INTRODUCTORY 
PRICE 



■^ 



$39900 




FREQUENCY RANGE: Receive andTransmit; 14400 
1o 148.995 MHz. 5KHzsteps(1000channe1sl. + MARS- 
CAP.* 

AIRCRAFT TYPE FREQUENCY SELECTOR: Large 
and small coaxiallv munted knobs select lOOKHz and 
1 OKHi steps respectively. Switches click-stopped with 
a home position facilllaie frequency changing without 
need to view LED'S while driving and provides the 
sightiess amateur w/ith fufi Brailie dial as standard 
eauipmem. 

FULL AUTOMATIC TUNING OF RECEIVER FRONT 
END AND TRANSMITTER CIRCUITS: DC output of 
PLL fed to varactor diodes in all front end RF tuned 
circuits provides full sensitivity and optimum 
intermodulatton rejection over the entire band. APC 
(AUTO POW.ER CONTROL} - Keeps RF output constant 
from band edge io band edge and helps keep spurs 
down. No other amateur unit at any price has this 
feature which is found in only Ihe most sophisiicaied 
and expensive aircraft and commercial transceivers. 
TRUE FM: Not phase modulation - for superb 
emphasized hi-fi audio quality second to none. 
4 CHANNEL RAM SCANNER WITH IC MEMORY: 
Program any 4 frequencies and repragram at any lime, 
using the front panel controls-scan all or part of the 
memory-search for occupied (closed) channel or vacant 
(open) channe^s-with internal Ni-Cad to retain 
memory. (No diode matrix to wire or change). 
MULTIPLE FREQUENCY OFFSETS: Three positons 
A,B,C- provided for installation of optional crystals: 
EXAMPLE 1 Mhz offset. Duplex Frequency Offset 
Built in - 600 Khz plus or minus 5 Khz steps, plus 
simplex, any frequency. 



• INTERNAL MULTIPURPOSE TONE OSCILLATOR: 

1 750Hz tone burst for "whistle on operation" andsub- 
audibie tone operation possible by simply adding a 
capacitor across the terminals provided. Internal 2 
position switch for automatli;. and manual operation, 
tone burst of sub audible tone"'PL - adjustable 60- 
203Hz(100 Hz provided). 

• RIT CONTROL: Use to improve clarity when 
contacting stations with off frequency carrier. 

• MODULAR COMMERCIAL GRADE CONSTRUC 
TION: 6 Unitized modules eliminate stray coupling and 
facilitate ease of maintenance.-. -- 

• ACCESSORY SOCKET: Fully wired for touch tone, 
phone patch, and other accessories. Internal switch 
connects receiver output speaker when connector is 
not in use. 

• MULTI-PURPOSE METER: Discriminator Meter, 
Provides "5" reading on receive and power out on 
transmit. 

• RECEIVE: Better than .25uv sensitivity, tS pole filter 
as well as monolithic crystal filter and automatictuned 
LC circuits provide superior skirt selectivity, 

• HIGH LOW POWER OUTPUT: 15 watts and 1 watt- 
switch selected-low power maybe adjusted anyvvhere 
between 1 and 1 5 watls-fully proiected-short or open 
SWR. 

• OTHER FEATURES: Dynamic microphone-mobile 
mount-external 5 pin accessory jack-speaker jack- and 
much, much more-size 2'/: x 7 x I'h. All cords, plugs, 
fuses, microphone hanger, etc. included. Weight 5 lbs. 



Manufactured by one of the world's most distinguished Avionics manufacturers. Kyokuto Denshi Kaistia, Ltd. 
First in the world with an all solid state 2 meter FM transceiver. 



(0 AMATEUR-WHOLESALE ELECTRONICS 




8817 S.W. 129th Terrace, Miami. Florida 33176 
Telephone (305) 233-3631 •Telex; 51-5628 
U.S. DISTRIBUTOR 



Dealer Inquires Invited. 

Please order from local dealer or direct if 
unavailable. 



196 




The New Sigma XR3000D 
Linear Amplifier 
Compare! ^m^ 



Features: 



Custom computer grade commercial components, capacitors, and lube sockets 
manufactured especially far high power use — fieavy duty lOKw silver plated ceramic 
band switcties • Silver plated copper tubing tank coil • Huge 4" easy to read 
meters — measure plate current, tiigh vo'tage. grid current, and relative RF out- 
put • Continuous duty pov-'ersupp'ybu!l; in ■ State of the art iener diode standby and 
operating bias provides reduced id'ing current and greater output efficiency • Buii! in 
tium free DC fieavy duty antenna change-over relays • AC input 110V or 220V AC, 
50-60H7 • Tuned input circuits • ALC-resr pane) connections for ALC output to ex- 
citer and for relay con:roi - Double internal shielding of all RF enclosures • Heavy 
duty chassis and cabinet construction and much, much more 



2 Da, A'Shipnienl 

Anywt-ereir. U.S £35 

Alaska and Hav.ai Sligtitiy Hicnsi 

' Full bandcoveraoe 160-10 meters including mars. 

> 2000 watts P.E^P. SSB input. 1000 watts input continuous 
duty, CW, RHY & SSTV. 

' Two Eimac 3-500Z conservatively rated finals 

■ All major HV and other circuit compcncnis mounted on 
single G-10 glass plug in board. Have a service orobiem? 
(Very umikely) Just unplug boarc and send to us . 
Heavy duty commerciai grade quality anc construction sec- 
ond to no other unit at any price! 
Weight: 90 lbs. Size: BVz" (1i) x 16- (w) x 15W (d). 



Introduclory Price 

$169 



HOLIDAY INTRODUCTORY SPECIAL! 

New! Sigma Model AF250L 
Deviation/Modulation Meter 

Features: 

Extremely stable local oscillator for easy measurement of HF, VHF, and UHF bands 
employing negative feedback, to insure extremely tiigh stability Easy to read, 
accurate linear scale • Direct off the air signal measurement capabiiity. 

Specifications'. 

Freguency: 1 .8MHZ-520[^/lHZ/3 range select (A, B, C, EXT}, A range: 26.5 MHZ-40(VIHZ, 

EXT. range: 1 .8MHZ-520t\/IHZ If^eed Signal Generator) -Generous overranges-lnput levei:(11 Through type input level: IW'200W (RF Input Ter- 
minal), (2) Direct input level: Mote than 80db;'50ohm impedance- Amplitude .modulation degree: 0-1003^ • Frequency deviation: 
0-20KHZ • Accuracy: '. /-3% of full scale- Intermediate Irequency: 10.7IVIHZ- Local input frequency (EXT Range')- Measuring frequency 
+ ,'-10.7MHZ • RF Attenuator: 0-60db variable • Audio signal oscillator: |1) Audio Frequency— 1 ,OOOHZ (1 KHZ), (2) Output level— More than IV 
RMS- Power Source: AC1 17V- Dimensions; H-SVj" (140mm), W-10W' |250nim). D-TVi" (184mm)- Weigfit: 7 lbs. 




\W WW 

range: 48MHZ-60MHZ, C range: 1'10MHZ-156MHZ. 




NEWCDEHAMIIIFIOTATOfiS- 
Heg-S159.95— S125 



V i'rioe 



Sigma RF-200Q 
SWR & Power Meter 

Cal PWR Scales 200W-2000W Freq Range 3.5-1 50 MHz Pieasfi do not con- 
fuse the RF2000 v;ith similar appearing lovk'er priced units. RF2000 is an 
individually calibrated professional quality instrument. Unequaied at many 
times tfie price. Size i" (w) x 2''?" (ti) x 2'3" (d) . 



fflKDK 



SPECIAL SALE 

FM 144 Accessories 



FMPS-4- Ki^umaK^I. r^ 



S-:j 
S5j 



.^1 ;■ Spill 
F:^-or 1 CIS;- Oi;: :n Pi ■,— ? 



FMUF-J r ■ 

fMTM Sin 
FM.A" 5 



:.ys- 



ff/.'r- 'i :-i I llll:Kjlj 
FM'S-2 ■ iMfPaUKTl 10 

I' ■ ;: > iil^J'jt f/-r-:M', S^:r 

FMVC-' iJi:' inMi -' v,i!iiB,|.-, ■.- 

T.jLCfl i j;it '"'.c Sbs 

FMTC-' Pfiv.:;-.„il " 1. .liiler 1ll( aS« «<! 

,-. l:I Pr i:jti !:.-i;iJ^ At^ ffjiipi 

TtlfOac S?b 

SC-12A 'iJiDlelntE.icM-iT De«-:.;- 565 ACCScc^eis PinDin Plai; 
FMSC-1 S'.ni'rr!.-— "(,;■■.. jii; .liyHs-iUB SW Ov/ne.-'i WSHLa! (Eilrj 
FMSC 2 Scadiiw Pii:i:,-i:iirr,:!',' 11 Se^' Co fvlamia: 

Ch-:;;uiclr, S6b Mounlir,g a.rac.sel lE.ilral 



.^l.ihi'.fiqiiiiitilll 
:■; Ml 

S13 

ill; 



; 1 : ' u. Hz 
"•:-.::-35lt l"?u3H/i 
'i 'X':j9. P nlA\)\'. .'i!iF:;ri,,H IG 

Lxlr-: QC Cod 6. ^lug 



S.- iCi 
SI M 
SiM 
Slffl 
SSM 



Standard New 2 Meter 

FM Transceivers 

Model SRC 146A Special Sale 



SRC-45..\ ... 

4 1i:6lsai SJantSi SA . 

US'JOaluxsgaisCliarge- 

F •■■.''■i Leaihet Case 



312 
SIC 

. . S3C 

Req Silj 

NEWl!! Touch Tone pad 
completely wired and 
ready to plug in-$69. 00 




New! Nye Viking 
Model MB-11 3,000 Watts 



o~o 



$285 



.;ntenn.i i-ipedanr,! N';:cTn; >;a*ojt( C3p- 
p:;: ■ibtJi-wCtMlrJ silvs-p|-^"SC ^oriaDleirc jc- 
■cr Heavy tjtv 7000 vc i variable oulDU' 
eapaciior 10.000 »o'i fixed capacilors. Si'ver 
plated IF jonauctors La'ge orKision, easy- 
lo-reaa dials 3B0' readcul Oueflcao prctec- 
\i(]!i fyrSWMrneisr. 



AMATEUR-WHOLESALE ELECTRONICS 

8817 S.W, 129th Terrace, Kllanii, Florida 33176 

COURTEOUS PERSONAL SERVICE— SAME DAY SHIPMENT ■ Prices sub|ect to change without notice. 

Telephone: (305) 233-3631 • Telex 51^5628 • Store Hours: 10-5 Mon.-Fri. ^^i 



liaitMdtlMID 


M 




Alias 210X-Z15X and 350-XL 



Please write for special 
bpms and package oltars. 



197 



i.2 8 




lUlSCCmEP 



H -tt^ 



% 




iV 






\n marc Lnttferr.i'j .iiaai.-. ijvei". I'mfiV-Oi: 
W3f«t tj ' I r y rf new f 1-5 j€a' 1 ■' ' 
j«>-l f'tii;-' ttn. 5.V!UhjCoi]Lr into the ha.-ti iifypif- 
r.tiJio, ^.'f.'Lii T.F).isnn I 12 .H-'il Lhi' bviuhaeocJer ■■ 
Iji'i-'^ Lti-ini"M3iiiJ t*t yonf Ftidi'i Giving vo-tii 
t]iif,''tUiJf.ofyfjo[ tii ALL Irp^.m riui'^^ 



H>f Mi < hanrtch, 

• (ullv Autumrftk lnvdlid Q)#.Coinrafl; 

• Fjl tory Wii L'd and Tptiod 

• E<i5\ To lnsia[l 






Engineering SpeciaUes 

P.O.BOX 2233 
1 i47COMMERqAL AVENUE! ^ :, 
OXNARD CA 93030 
1805)486-0817 



;;:;:;:l. I'LiLjEtlftl Rtea5e;send more info. 

':':■:: L l"M H9©KED; KtpaisB RUSH nhv SynlhacSiler. 



.■:tHlV^_l. 



YES, I wottUi iikt- to purchase aiSynthacoder fttr iiiv ■ j;G-22.S. 
Enrlosed pteaw fiiKi fnv- i&9:95"-.:'Prk(? jnciudei postage and 
handling) C.iJiitorwa regents add. fet-' sai(V> cax; Offtr. eRd'> 
n/30;77. 

S, enclo:,«d. S-Gash' J Gheek' i^Mbney-Order 

Pl-ease charge my lj Master Charge :~1 BankAtrJerit jflI 

Credit card ^ ^^ .- ■ ■- 

Interbarik = „ ^ 

Exptration date . 

Signature ^i^^__„ — : —^ ■■-- '^^ 



>■ 



Xall. 



..iiMte- 



Zip . 



E12 J 



THIS AD MENTtONS QNLV A FEW OF THE THQUSANPS OF BARGAIM ITEMS AVf^l.LAflLE FROM THE GIANT Bi^F CATAL.QG. CIRCLE THE fi£ACJER SEftVIC£ CARD FOR QUR CATALQQ 



12" 

Video 

Monitor 




This solid slate monitor will display 80 
characters x 16 lines for a total of 1.260 
characters. These ^re ready lo attach to 
your computer or CCTV. Operates on 
115VAC, video input to 75 ohm.SO-239 
C03X connector. Qiy. Ltd. Used a^d 
guarenteed. Sh, Wt. 35 Lbs. 
7HU70398 S68.8B each 



HONEYWEL 
SMOKE te Jj 
ALARMS 



Dual chamber ioni?.alion detectors sense 
tir\y airborne particles of combustion in 
a fire's earliest stage even before there's 
smoke. Operates on 1 15VAC, UL listed. 
Sit. Wt. 3_LtK. . . 7MI 70349 . . .$24.38 




L 



aciiii^i. J 



0to20 
DCAMMETEI 



Large 2-3/3" ?qLiare ?ee-thru plastic cov- 
ered n-ieters. External resistor req. Super! 
Sh.Wt. 802. . - 7W70343. . . S2.00ea. 



TV-COMPUTER: 
li 



I gllGOHtt 

INTERFACE KIT^-^g^ 

Converts any standard TV into a comput- 
er monitor. This self-contained RF oscill- 
ator 8i modulator allows easy interface 
oi any video output device to a standard 
TV set. Thiii kit was part of a video game, 
and contains its own power suppiy. With 
instructions 8* data^ 

Sh. Wt. 3 Lbs, , . .7ZU70213. . . .$7.88 
■^ tor SIB 00. . . 7ZU70213 . . S4S.0O/7 




MLAflLEFROM 



SPEAKER KITS 



Bufid your own and save! These kits are 
made up of quality components intended 
for use by a big-name rt^fr. iwho we can't 
mention). Over S2 million iri irwentorie^ 



SUPER SURPLUS SAVINGS! 

'were dosed out[ His loss your gain I Kits 

are 1^ qusiity. all U.S. made. Cabinets 

are vinyl-dad with precut holes, grill 

cloth Is included. Perfect for those do it- 

yourself-ers! Two types of kits available; 



SPEAKER SYSTEMS KIT No. 1 Our deluxe model . 




Super cabinets, size 21x12x8". Includes 
8" woofers w/whijzer; 4" dome Tweeters; 
crossovers; damping; hardware & instruc- 
tions. Systems sells for S19S if bougi>t 
readv-to-go, B&F kit price only S69.9S 
per pair. QuaSity need not be costly! 
72U70283. . . .(46 Lbs.} . . . S69.95/pr. 
Kit No. l/CABINETS Only |45 Lbs.) 

7OB70!97 S25.00/pair 



SPEAKER SYSTEMS 
KIT No. 2 

Fantastic cabineis desigr^:! for direct 
dispersion of high frequency sounds dnd 
v.'ide dispersion of bass tones Size: 1 7x 
lOSxQVi". Sold ivnh 8" v.'oofprs, 4" 
dGFT^e t^veeters, crossovers & instructions. 
7ZU70242. . . (35 Lbs.) . . .S'lS.SO/pair 
Kit No. 2.'CABINETS Only 125 Lbs.i 

7OB70200 S2S.00/pair 




LOGIC & 
OP AMP 
POWER 
SUPPLY! 



More SPEAKERS & COMPONENTS 

. . . are available through our catalog! 



Computer surplus cioseout on Singer 
F-'iden Md. 52 tine printer. IQO lires per 
minute with 132 characters pc^ line max. 
The printer is connected to a system com- 
puter through an input/outpu! channel 
and may be located up to 2,000 wir? feei 
from computer using a 2 wire line. Uses 
standard continuous paper forms, with up 
to 5 copies and 1 original. Power: n5V, 
60 Hz; 6 amps. Size: 30"W x 27"Dp x 
38"H. 

These units were working & going units 
when tai<en out nf service. Shipped only 
on an "AS IS" basis. You should be able 
to put these on line with a minimum of 
work, and then you have a S3, 600 line 
printer working for you at less ihan 1/5 
the cost. Shipped via truck freight collect 
toyou, F.O.B. Peabodv,f\fla. 01960. 
7SF70298 $650.00 

DATA MANUALS, while they last . 
7SF70Z98-M $45.00 

Also available are a few damaged units, 
which have broken glass covers, Damage 
appears to be cosmetics only. Save SlOO. 
7SF7ii299 S550.Q0 



Line Printer 




Sirtger-Frlden 

Md. 5Z Line Priirter 



KeytoTape Recorder 



SDESK-TOP I/O TERMINAL 



At one time ihese data terminals were 
used by stock brokers for keeping track 
of stock quotation?. They lied in to a 
central system which has now been up- 
dated, leaving thess surplus units oehind. 
Use this unit as a basis for building your 
own computer input/output station or to 
build a compact scope ... or simply take 
it apart for the components within. 

Sold complete or in parrs, prices and 
descriptions listed below: 
13" CRT. witfi Hi-volt. siJpply E■^3315 
vdc; —1730 vdc). and low volt, supply 
■^440V; t225V; +125V; +28V; ^1.2V: 
+0.6V; B.SVDC; 6.3V AC. Also - ramp 
generator card Sk some drive circuits 

(15 Lbs.; . - S17.50 

t 50 key Block keyboard, with diode 

matrix on 2 cards.15 Lbs,J S12.50 

t Handsome desk-top, slope front case, 
suitable for up to an 11" CRT, overall 

lOy^wxlGd x9"h.ll0 Lbs.J S7.50 

t Plus: 3 wire line cord, brown. 7'lg for 
$1 .00; 14 wire connector cable lor 
S2.50. 
t COMPLETE UNIT Sh. Wt. 35 Lbs. 

6NB60336 329.95 

r Also available is a complete tecli. man- 
ual covering operating procedure, theory 
disassembly (& reassembly), trouble 
shooting techniques and schematics. 
With complete unit - $1.00 or sold sep 
arately for $3,50 each. Sh. Wt. 3 oz. 

WHEN ORDERING: 
SpecHy part, i>se order no. 6f^B60336 




■■S^j. "^ 



^~ n^er^Pertec systems j/i''i d jplay >'".)- 
tron, keyboard, 7 track magnetic da 
reorder, controilsr, etc. Singer closes 
out its computer products division and 
these unit become surplus' Their los5 
(S460x10'') IS your yain . . . you can b-jy 
this St: per recorder ior pennies on a do( 
lar. They are late design modet? of recent 
mfg-. and are slJlJ being scpjiced with_ 



PLASTIC CABLE CLIPS 

Unique 12" strip, self stick backiriy. Yt" 
high. Use whole or cuL into smaller parts 
CO give up to 24 - //'cable dips. Handy! 
Sh.Wt- Soz. . 7K70354 . $1.25/2 strips 



POSTAGE; Please add sufficient funds 

for postage and insurance. Shipping 

weight for merchandise is listed at the 

end of each product description. All 

shipping is from Peabody, Ma. 01960. 

Mass. Residents Add 5% Sales Tax. 

SEND FOR OUR FREE CATALOG! 

Or, receive our catalog in 

an order and insure yourself 

of a place on our mailing list 



backup. Unit has internal memory/buffer 
lor SO or 200 character storage. Units 
show character, character no_, and record 
no. Head back circuits allows search on 
record key, editing, dupl icating, etc 
Units were working when taken out of 
service and are complete & ready to-go, 
hut may require minor adjustments. Sold 
On an "AS IS" basis only. Manuals not 
supplied v;ith unit, available separately. 
Size: 19"H x 21%"W x lOV/'D. Tape not 
supplied. 

We have 2 types available: 
Md. 4301-7 7 track Data Recorder, our 

catalog no. 7SF70296 5218.88 

Complete Manual .7SF7p296M .S28.5Q 
Md. 4311 7 7 track Data Recorder with 
remote data communication channel, our 

catalog no. 7SF70297 . . . S248.88 

Complete Manual .7SF70297-M .328.50 
(Manuals weigh 3 Lbs.J 

AIL Magnetic Tape Data Recorders 

are shipped via truck, freight collect 

to you. Customer pays shipping. 



AM/FM stereo 

TUNEF(/AMP CHASSIS 
only $18.88! 




New surjjlus stereo tuner & amp. 4 warts 
RMS pef channef. Super-slim unit mea- 
sjres onfy 2%"H x I2y/"L x 8"0. Con 
trols include baJ., tone. vol. -on/off, AM/ 
FM/FM stereo AFC/Aux. selector and 
Tuning. Dial lias red needle and black 
face with no markings. Sh. Wt. 6 Lbs. 
7HU70397 $18.88 each 




Surplus from a computer phon-;. V-j^-er 
supply is regulated, input of 115V 60Hz., 
cutouts of ^.12V (51 .125A. +5V @ .75A. 
Uses (3) 723 voltage regulator IC's for 
regulation. Open frame type, Oiy. Ltd. 
Size: ?.2"L x 5.6"W x 2"H. New. 
Sh.Wt. 5 Lbs. . , 7MJ70353 . . .S13.50 
3 for $38.88- . , 7M 1 70353 . . $38.88/ 3. 
10 to 24 VDC, 2 Amp qpEM fO^ 
POWER SUPPLY KIT cS'^'- 

A complete kit which puts out 10 to 24 
VDC at 2 amps, regulated. 115 VAC in. 
Can be wired for contant 13.8VDC, ideal 
& compact for C.B. Kit includes PC card, 
components and instructions . . just add 
your own case. Super as a bench supply! 
Sh.Wt. 6 Lbs. . .6C60498. . . .$14.88 



4 in 1 TV GAME 

: CONTROLS 




Features 

a hockey mode in vwhich players skate up, 
down and accross the ice using the joy- 
'stick, with the ability to "catch" the 
puck and "shoot" for goals with another 
control. A real challenge for ail players. 
LED readouts show score, operates on 
1 15V fiOHi:. Never at this Jow^jrice! 
Sh. Wt. 5 Lbs. . . 7HU702a4 . . . $22.50 
5 (or S 100.00. . 7HU702a4 . .$100.00/5 



^ 



JOYSTICKS 
Two 10K POT'S 

Super for X-Y func- 
tions: audio, computer, 
remote control, graph- 
ics, etc. Sh. Wl. 8 or. 
7J7D163 $4.95 



Joystick -Four 100K Pot's; by ALPS 

The best controls on the market. . . 8 oz. 
7J7Q293 . - .55.95 ea 



RADIOSONDE with SENSORS 

This radiosonde is used by meteorologists 
for upper atmosphere 5tiidie5 of pressu^^e,. 
temperature & humidity. Package has 
temp, sensor, hygistor, barograph, etc. 
Tinke/^er's delight lots of gadgets! 
Sh. Wt. 1 Lb ... . 7F703&4 $5.00 



OTHER SINGER/FRIDEW MACHINES 



SEISMIC SENSOR/XMITTER 

-1 A whaler This unique looking Sl oper- 
ARE AVAILABLE SEND FOR CAT ALOGgiiona! intruder detector/xmitter was 

used by the US. army to detect troop 



PHONE ORDERS WELCOME! 
Bank Americard, Master Charge and 

American Express Accepted. 
Phone: (617) 531-5774 / 532-2323 
$1 0.00 Minimum on Charge Orders 

B&F ENTERPRISES 

Dept. "S" 
119 FOSTER STREET , 

PEABODY, MASS. oigeS"! 

(617)531-5774/532-2323 



movements. It looks like a rock Or glob 
of mud, but contains: a trasmitter with a 
range of 300 meters that sends out coded 
pulses on 150 MHz; a built-in dipole an- 
tenna; seismic sensor; Si 3 mercury cells. 
Weighs about 1 ounce, measures less than 
2" across, Fantastic! Sh. Wt. 3 oz. 

7MI70365 . . . $4.00 ea . . . $10.00 for 3 



PHONE ORDERS WELCOME! - {SI 71 531-57 74/532-2323 — BAN KAMEH ICARO / MASTER CHARGE / AMEHICAt^ EXPRESS CARDS ACCEPTE 




199 




Frequency 
Counter 

$7995 



kit 



CT-SO fr&fpjgpcy counlsf 



|S5.310H55| Jrj% 



111, . 1 V 



UTILIZES NEW MOS-LSI CIRCUITRY 



You've requested it^ and oov/ it's here! The CT-50 frequency 
counter kit has more features than counters selling for twice the 
price. Measuring Trequency is novu as easy as [Pushing a button, the 
CT-50 will automaticatly place the decimal point in all modes, giving 
yoo quick, reliable readings. Want to use the CT-50 mobile? No 
problem, it runs equally 3S well on 12 V dc as it does on 1 1 V ac. 
Want super accuracy? The CT-50 uses the popular TV color burst 
freq. of 3.579545 MHz for titne base. Tap off a color TV with our 
adapter and get ultra accuracy — .001 ppml The CT-50 offers 
professional quaKty at the unheard of price of S79.95. Order yours 
today! 

CT-50, GO MH£ counter kit , . . . $79.95 

CT-&0 WT, 60 MHz counter, wired and tested 1 59.95 

CT-600, 600 MHz prescaler option for CT-5D, add 2QSS 



SPECIFICATIONS 

Sensitivity: less than 25 r^v. 

Frequency range: 5 H? to 60 MH^, typicaJly 65 MHz 

Gatetime: 1 second, 1/10 second, vi/ith automatic decimal 

poini positioning on both direct and prescale 

Display: S digit red LED A" height 

AccLiracy: I0ppm,.00l opmwithTV time basel 

Input: BNC, 1 megohm direct, 50 Ohm with prescale option 

Power: 1 1 V ac 5 Watts or 1 2 V dc @ 1 Amp 

Size: Approx. 6" x 4" x 2". high quality aluminum case 



Color burst adapter for .001 ppm accuracy 
CB-1,kit 



.$14.95 




CLOCK KIT 

6 digit 12/24 hour 



Want a clock that 
looks good enough for your 
living roon^i? Forget the com- 
petitor's kludges and try one of 
ours! Features; jumbo A" digits, 
Polaroid lens filter, extruded aluminum 
case available in 5 colors, quality PC boards 
and super instructions. All parts are included, no 
extras to buy. Fully guaranteed. One to two hour, 
assembly Time. Colors: silver, gold, black, bronze, 
blue (specify). 

Clock kit, DC-5 $22.95 

Alarm clock, DC-8, 1 2 hr only 24.95 

Mobile clock, DC-7 25.95 

ClocE^ kit with 10 min ID timer, DC-10 . . , 259 5 
Assembled and tested clocks available, add 
SI 0.00 



CHEAPCLOCK KIT $8.95 pcao^rd 

DCA Featurtr^: Doe^ not S2.95 

• 6dLgil .4" LEH include buard Transforrtie 

• 12 or 24 foimai or ifansform&r Si .49 



600 MHz n^=^ 

PRESCALER tO^P 

Extend ifiy range of yo jr 
counter Tc 600 VHz. Works wjth 
3fl counters Less than 150 mv 
serssiTivity. Spocifv "^10 or "n 00 
Wjrec, tested, PS 15 .... S59.35 
KK, PS-IB . . S^d.gs 



VIDEO TERMINAL 
KIT $149.95 






r ASCII rti-JDiuVi ■^i&':lt ivo* ie-E'-:?-r-^ 

njig c.irrsor Alig C-ImM f JOe. ■ft1c■iI^S 
2, Taads rrtini i!> w .i^amDi-,.. The 
^tOO r-na arid pbhIbuH slanaorj /B 



1 fit hi\e, t-lKy< DJ133 1 a 



CAR 
CLOCK 
KIT $27.95 



•Super in^t'^ti^fK 




AUTODIMMER 
52.50 



30 watt 



2 meter 
Power Amp 



The famous Ri; class C t^ — ,„. 
ainp now avatlabli^ mail order! Four 
^'VdlK in for 30 WflU-i out, 2 iu for ^5 
oyt, 1 in for 3 out. incredible vatue, 
coinplete iviih ail par^g. irislrucTion^ 
and d&tails on T R reiny. Case not 
ir^cl jded. 
Comolere Kit, PA 1 S22.95 



CALENDAR ALARM CLOCK 






Cumpl^Te Kit, iess case, 

DC 9 S34.S5 



5314 Clock 

7asoo 

743112 

7447 

7473 

7475 

7490A 

74143 



$29 5 
.3S 
.75 
.79 
.35 
.50 
.55 



555 
556 
566 
567 
1453 



S ,50 
-75 
1.49 
1.49 
.50 



LED DRIVER 
75491 .50 



REGULATOR 
78MG Si 

309 k 
309 H 

340K 13 ^ 
7805 O" 

7S12 <^ 
7315 ^7 



TRANSISTORS 
MBF 23S30i\' VHF 
NPN 2N3904 lypi; 
PNP 2N390S tvps 
NPrj Power Tab40W 
PNP Power Tab40W 
FET MPF-102 tvpe 
UJT 2N2646 type 
2N.305S NPN Po^/Jer 



S11.95 

lO/si.oo 
10/ SI. 00 

3/Sl.OQ 
3/SI.OO 
3/$2.00 
3/S2,00 
.75 



DIODES: 1KV.2.5A - 



100V. 1 A 10/$1.00 INalflA typE S0/S2.00 



LED DISPLAYS 




F\:D 353 75 

FKD 5'.0 .... 1.25 

UL 707 1.25 

HP 7730 .... 1.35 
ptea Polaro d F li^r . fl.^S" X 



741 OP-AMP SPECIAL 

Facloiy prime mini d>p Wuh both 
Xerox and 741 part numbers 

lOfDrSZ.DO 



.59 



SOCKETS 

14 Pi\. 5;si .00 
iaPiu 5.'si.oo 

24 PIN 2.'S).00 
40PII^ 3.'S2.0a 



FERRfTE BEADS 

^\iir\ infc niid 5pecs 
' 5,'S 1 -OC 

6 It^IiT- Baiur' Besds 
5/Sl .CD 



rsfnsB!^ slssircniss 

P.O. Box 4072 Rochester NY 14610 
(716)271-6487 



TELEPHONE ORDERS 
WELCOME 



taH 



Satisfaction 
gu3r3rit«ed or 



COD. add 
S1.00. Ordi 
undor SI 0.00 
iidd $.7B. NY 
rcsirfcnta add 



MINI-KITS 



TONE DECODER KIT 

mfUB. i^h^jd -egdat^n. ij&7 L". L^il-J 'o' 
;:>jck'-'iunEiLtei;H)inc|. Li^llif Uiri' dslariiun. =SK 
ctMiiWd. iifffw/wiq. ar>d r:-t^j- ^Ihtr usb». Use 7 
to* '2 Uunon '.a^xii^oni ceoiji^p. Ruris on E 
13 i:; *.Miii. 

ComplH-w Kit, TD-1 _ 53.95 



# 



SUPER-SNOOP AMPLIFIER 

A super-sensitive amplifier wiiicli will pick up a 
pin drop at 15 feet! Great for monitoring 
baby's room or as a genersi purpose test 
amplifier. Fuil 2 watts of output; i;uns on 6 to 
12 volts, uses any type of mike. Requires 8-45 
ohm speaker. 
Complete Kit, ei\]-9 S4.95 



FMWlR&LESS MIKE KIT 

Transmit up lo 300' to any FiVi broadcast radio, 
uses any type of mlkc. Runs on 3 to 9 V.Type 
Fr\/l-2 has added super sensitive nnike prearnp. 
FM-I $2.95 FM-2 , .-. V. . $4.95 



COLOR-ORGAN/MUSIC LIGHTS 

See music come alivel 3 different lights flicker 
with music or voice. One light for lows, one for 
the mid-range and one for the highs. Each 
channel individually iidjust^ble, and drives up 
to 300 watts. Great for parties, band music, 
fijte clubs and more. 
Comptete Kh, ftrtL-1 S7.95 



LEOBLINKYKIT 

A great attention getter which slternaiely 
flashes 2 Jumbo LEDs. Use for name badges, 
buttons, or warning type panel lights. Runs on 
3 lo 9 volts. 
Complete Kit S2.95 



POWER SUPPLY KIT 



Cornplei? 

artf] Small ; 

G-E V i!T I Afni>gnd ie tq 30 VCT, 

Complex* Kii, re-3LT Se.95 



regufatflci |>ow»r supply pro- 
Ei voiti fti 200 rriA jrid fS yalts 
\/ load recjuk-itiori rjuod liLte-rir^g 



4r 



SIREN KIT 

Produces upward and downward wait char- 
acteristic of poiice siren. 5 watts audio output, 
runs on 3-3 volts, uses 8-45 ohm speaker. 
Complete Kit, SIVI-3 S2.95 

"decade counter parts 

Includes; 7490A, 7475, 7447, LED readout, 
current limit resistors, and instructions on an 
easy to build low cost frequency counter. 
Kit of parts, DCU-1 S3.50 



200 



R8 



ADVA 




KIT $1186 

ASSEMBLED $17.95 
ADD $1.25 FOR 
POSTAGE/HANDLING 



VARIABLE POWER SUPPLY 

• Continuously Variable from 2V to over ISV 

• Short-Circuit Proof 

• Typical Regulation of 0.1% 

• Electronic Current Limiting at 300mA 

• Very Low Output Ripple 

• Fiberglass PC Board Mounts All Components 

• Assemble in about One Hour 

• Makes a Great Bench or Lab Power Supply 

• Includes All Components except Case and Meters 



FREE 



iCor FET's WITH 
S5S- SIO ORDERS.t 
DATA SHEETS 
WITH MANY ITEMS. 



DIODES 
RECTJFlEflS |2K11S 



TRftMSJSTOBS |TftAWSI£TORS TRAKSJSIOBS |Ll«EAF[IC's 



IK IK' 



IMIHI 
ISM!M 



ismiiKZis 



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M.H 


JHwr 


JAl 


.liiMwit,:: 


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U.HLmM^ 


3/11 


IsWiimiMJ 


^11 


U.^IitiiiJd 


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OTHER ADVA KITS: 

:t .u -^.^ ij^ic:;. "ttl _ tl rtl, ^TL -i' 
«ir ■*^»jl r-^i-tfllfun trf i:,5fl «»i* thEiE 



llfititbEI PC b 



q.ivl!sl« 






5. AdiiSLiS a-A vi; (ur 



MORE SPECIALS: i# 

' S^iiiA VOLTAGE REGULATOB LC. Ve^y ftesy lo 
r UrTlY rtigalaled -15V Supply far OP AMP'i. ttc. 
ii-Kji^lji*il CC (1E-30V) and 2 hypais capacitors. 
.fi.j i.H*-i^^,nitj. S pin mDIP SI, 25 



OBDER TODAY . 



. ^Lipl. 



AlPlii 

WRITE r-an Fl^Efr 

Silrtil iSifitjifTifi, 



riATA :iHtF75 iLpplifil wil'i riiniiv items from tnli sd. PHEE ON 
imp w::ll ri/frV irdir 0l Slj ti' iriOrt -TilS Dl^l Q? AiTip- Qf TiUC E^DQ 

■ of 1 1 (IF ill. If (v. i;i:;:i™rl^^!l ijripr to j.':] 1/77 Dns frss ilam l»r ordu. 
ir■■ll^', ',LiWi;i;i w u'ior lai* .na pnci;! 5ubj7« w •Bt's^ngr f^.'fl.hoijt ri^Bcs. 

J■lllJ'1■■-lOU%1^Jl1':l^om|llv L-JJifr). 

CaTAI.06 ^7G allsrin^ at-ir 3OT Mmirerriucmit cjiiiptl m iiock 

■r ifioniiy aian iU S luftds) wltii tir<j-i'. IVi! p.-iv 1" Class postsga !i U.S., 
Mt'ol ^11 knO £1.00 ^ihinJImg chj'j« sr ardors urd^ £10. Calt^ la^i- 
l^nrHji|]rir.ii;ijfiadiJpDiiMi; COOoidrrj 3tJrr!],00sKr^iwcKara-. 



R^uirH .^nlw 

'."iith Dji.-i S^wvl 

LM741 FREOCOMPtNSAl tLJOf' A.^IP. ;jA7-11, ^^C1741. etc. mDIP 5/31 
rwC;4S3 DUAL 7-11 OP A.MPinDIP 3/Sl 

RCdB^S DUAL 741 OP AMP riiCJIP 3/S1 

3N3fO-I [^PN TRANSlSTOfl AMPLlFlER;SWITChto50n>A p'100 6/Sl 
2£NeRS-Speci(v VolirttjH 3.3.^9,4.3.5.1. 6.8. B.2 lOOm^'V 4/51 DO 

9.1, 10, 13, 15. 10, '3. SO. 22,2.1. 27. or 33V t^lOStl T ^^Vatt 3/S1.00 

• MONEY-BACK GUARANTEE 

• ALL TESTED AND GUARANTEED 

ADVA 

BOX 4181 K , WOODSIDE, CA 94062 
Tel. (415} 851-0455 



f1 $]2VH: 

SltflSMte 

"*VI3;? 
WV22tll l: 



Si i«ti-;; 

_ TlllSfi 
ZWIM 

^ zwit; 
^' I'lUdJi 



Iit6 

Ikpl 

LIN. 

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ll«!5' 

1112 

iijniH! 
«K!±diH: 

^>ll :U»tr! 

:-?|:UUZ£ 
Zl^l 'i:d1] I'D 

w.w' ru-15 

■■In, 



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"^ IMIW 

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<E.f I ! amii 

) II MtlrU 

t.£l MtU-l 



rnr^iAL ic'i 

'"lilM^nik £L9S 

t«i*— ^ .16 

«.n m-wiin « 

^ m^riH IB 

_ il -DTimfl II 
^^|ifl.4rH IE 
liSI ■* '**** ** 
J.^1 illLARlC'i 
Jl U ktaiHH l.iU 
1 ^ .hU-U j? 

£d3i cH^li Ik 

Ml JHWK Mi. 

1>Ei JUI1IR 41 

SIM lUi;iK5 1T5 

Z.M LUITGKIZ ^n 

V7.» LUTCKIS ^]i 



IUJ4DT-5 
i-Dk:dT-G 
Jlll]aDT-l7 

■ injinr 15 
iiiiaoTja 

I LMI77'i 
LWjOT. 

■ LUTtSCk 

' lujim 

\iLWJ2ifi- 
: l.UTa\ S 
jLKT«:CH 
'LH7<1CN" ■ 

iiHKICH 
HJUB«- 

HKdC*' 
Mi If- ■! IT 

LM7II1X £ 
Tiiiif 

CAiin-i 

LKl?ri,i;! 

I y\y.'.7\ 

?Ch TiTSt' 






*SUPER SPECIALS: 



ELECTRONICS 



1N914 lOOV/lOmA Diade 
1N400T lOGV/lA Rec! 
irJ4154 30V 1N9U 
BRI 50V i^A Bri(Jpeftec 
aN:;222A WPN TMniiUfir 
2r029O7 PNP Translator 
2M3055 Power Xisior 10A 
2N3904 hlPrJ An^i)/S™ .ilOO 
2W3906PNP AiTip/S^w^nOO 
GPBBO Power FET ViAmp 



IS/SI 

6/S1 

6/S1 

6/$1 

$S 



3/S1 
S1.7S 



IVtPFIOaSOOMH^BF Amp 
40HT3rL1OSFETRF Amp 
LM324 Quad 7d1 OpAmfl 
LM37E PosVoURag mDiP 
ME5S5 Timer niDiP 
LM723 2^3?V Reg DIP 
LM741 Gomp Dp Amg mDtP 
LM145S Dual 741 mDIP 
CA30S6 S Trani Array DIP 55 

RC4195DN ISVysOmAniDIP 1,25 



Zf$1 
3/$l 

3/$1 



RF301 RF Poiivar Amp Tramjstor lll'?5W (^.a 3-30MHz TO-3 S5.00 

55SX Tinier 1(js-Thr Different pinOLJt Ironi 555 [w/dais) 3f^$1 

RC4194TK Dual Tracklny PugaJiitur O.K lo 30\r e 200mA TO 66 S2,50 

RC4195TKDualTracltdniiRfiat'lntQr ISV 6? lOOlUA [TO-66: S2,25 

3033 Waueforni GewratOr Vl lA Waua WiUi CircuJts & Data $3.75 



SPECIALS -THIS MONTH ONLY 

1N34 Germanium Diode 60V 10mA 10/$1 

1N6263 Hot Carrier Diode (HP2800, etc.) $1.00 

2N918 UHF Transistor ~Osc/Amp up to 1 GHz 4/$1 

2N3866 UHF Transistor-1 Watt at 432 MHz $0.75 

RCA29 NPN Power Amp/Switch SOW TO 220 .70 

LM741 Compensated Op Amp mDIP or DIP 6/$1 

LM1304 FM Multiplex Stereo Demodulator $0.99 

LM2111 FM IF Amp/Limiter/Detector .99 

CA3028A RF/IFAmplifier DC to 120 MHz 1.45 

RC4136 Quad 741 Op Amp- Low-Noise .95 

LP-10 LOGIC PROBE Kit-TTL, CMOS, etp. $7.85 
(See Above-"OTHER ADVA KITS") 



ADVA 



ELECTRONICS 



BOX 4181 K 
WOODSIDE, CA 94062 
Tel. (415) 85V0455 



A24 



20f 



BiLLEI ELECTB«IIC9 

PHONE ORDERS ON MASTERCHARGE OR VISA CARDS 



P. O. BOX 19442E 
DALLAS, TEXAS 75219 
(214) 823-3240 bs 



J PS-14 HIGH CURRENT REGULATED 
'W POWER SUPPLY KIT 

A low cost, no frills, heavy duly power supply. 
Designed for use and abuse! 

12V @ 15A Less Case. 

' ^ i-J^A mpters & lacks 

Better than ZGOMV loiiciS line regulaiion pi.^lcis ux jat.i\3 

Foldback Current Limiting 

Short CiiCgil Protected 

ThefTial Sliu;do'-"-n 

Adjustable CurrenT Limiiing 

Less ttian TK ripple. 

15 amps 11.5 to 14.5V 

All par Is supplied includincj heavy duty 

transfornier. 

Quality plated fiberglass PC board. 



$39.95 

UPS SHIPPING 
PAID! 



PS-t2: SAME AS ABOVE BUT VARIABLE OVER 
3-30 VDC IN 2 RANGES. 849.95 

(without thermal shutdown) 



A COMPLETE CAPACITOR DISCHARGE 
IGNITION KIT for $9.95 

^ou qet all the e!e~tronics less [lie case and heat- 
sinks. 



SPECIAL SALE! The response to oji arnii^'ersu' v sals 
on COI's was fantastic so here goes again, , WHI LE 
THEY LAST. _. Buy two CDI kits for 39.95 eacii, get 
the third CDI kit for SI. 00! 



MK-05 MINI MOBILE CLOCK 

The smal'est and best pr'ced ;r.obile clock kit on the :r,ar 
ket. Designed to be a nnobile cIcck frbm the ground uf). 
There has been no compromise on, quality. 




J 



FEATURES; 

* Quarts crystal timebase 

' Toroid & zener noise & overvoitage protection. 

* iVIagnified .15", 6 digit LED readout. ^y^ 



Complete with presettable 24 hr. alarm 

9-14 VDC (3 40 to 50 ma. 

Readouts can be suppressed 

EASY, QUICK ASSEMBLY 

All components required 

speaker), 

Top quality drilled and plated PC boards 

Clock board; 2.6" x 2" 

Readout board: 2 3/8" x .75" 



112. 



With punched front i 

alummum case — SI 5.95 



included {you supply the 



Small enough to 
mount in the 
histrumenl panel! 



SPECIAL! METERS 

LARGE, QUALITY 3'A RECTANGULAR METERS 
AVAILABLE FOR USE WITH OUR POWER SUPPLIES. 
DIAL CAN BE BACK LIGHTED. INDIVIDUALLY 
PACKAGED WITH MOUNTING HARDWARE. NEW 
DESIGN REQUIRES MUCH SMALLER CUTOUT THAN 
STANDARD IVIETERS. 

0-15V DC 7.16 0-15 ADC 7.16 

0-25V DC 7.05 0-25 ADC 7.05 

DEDUCT W% IF ORDERED WITH PS 14 OB PS 12 
POWER SUPPLY. 



OVERVOLTAGE PROTECTION KIT 

Provides cheap insurance for your expensive equipment. 
Trip voltaqe is adjustable from 3 to 30 voits. Overvoitage 
instantly fires 3 25A SCR and shorts the output to protect 
equipmert. Should be used on units that are fused. Di- 
rectiy compatible with the PS-12 and PS-14. Al! electron- 
ics supplied. Drilled and plated PC board. (Order OVP-1 1 



$6.95 



2N6283 MOTOROLA HOUSE # DEVICE 

^ 20amp NPN Darlington with Hfe 

ff 1 f\f\ 0' over 5.000! VCE of 80V, Out- 

'^ I *\J\3 performs MJ3001 and MJ1000 

" devices. -TO-3. Limited Qty.l 



Free Money $$ Free Money 

Starting October 1, 1977, each Bullet catalog will be 
stamped with a different special code number that will 
be placed in a monthly drawing. The monthly prii^e will be 
S100.00 in cash! The winni^g^number will be announced 
each month in this ad and the winner will have until 
the 20th of the month to claim the money. No purchase 
necessary. Catalogs are available free upon request All 
orders receive a catalog. Watch for your Lucky IMum-ber! 



Multi Colored 
Standard 




c 



202 



lRiIbb®n Cable 

26 conductors of no. 28 standard wire with a woven 
binder for easy separation. Super flexibility. For com- 
puters, and other projects. 10' ROLL 2.95 
50' ROLL 9.95 

No. 30 gauge silver plated wire wrap "wire with Kynar® 
jacket, 500ft. 5.'"" 



MINI ELECTRONIC 

GRANDFATHER CLOCK KIT 

Complete Electronics! 
' Chimes the hour fie; 3 times for 3 O'ciockl 

Unique "swinging" LED pendulum 
' Tick tock sound matches pendulum swing. ,»,^-»«- 
' Large 4 digit .5" LED readout 539 95 

• All CMOS construction 
' Complete electronics including transformer & speaker; 

drilled and plated PC boards measure 4,5" x 6.5" 

BEAUTIFUL SOLID WALNUT 

Custom case for above kit. Over 9^/^'' tall. $19,95 



No COD'S. 
Send check or IWO 
MasierChsrge or VISA accepted. 
Texas Residents add 5% sales tax. 



• Foreign orders add 10% {2.0% airmailj 

* Catalog included with each Drder 

^ Orders over $50. take 10% discount. 



All phone orders over S10. from this ad 

SPECIAL will receive a FREE Warble Alarm Kit 

($2.50 value). PHOME ORDERS ONLY! 







NEW LSI TECHNOLOGY 



FREQUENCY COUNTER 



TAKE ADVANTAGE OF THIS NEW STATE-OF-THE-ART COUNTER FEATURING THE 
MANY BENEFITS OF CUSTOM LSI CIRCUITRY. THIS NEW TECHNOLOGY APPROACH 
TO INSTRUMENTATION YIELDS ENHANCED PERFORMANCE, SMALLER PHYSICAL 
SIZE, DRASTICALLY REDUCED POWER CONSUMPTION IPORTABLE BATTERY 
OPERATION IS NOW PRACTICAL], DEPENDABILITY, EASY ASSEMBLY AND 
REVOLUTiONARY LOWER PRICING! £11095 



K!T#FC-50C so MHZ 

KlTfiPSL-650 350 MHZ 

MODEL#FC-50WT so mhz 

iMODELftFC-50/600WT. . 6M mhz 



B F TO ItltTJ OB lciM»e- 



I ■ W I 



COUNTER WITH CABINET S. PS. . . ■ ■ «* COMPLETE! 

PRESCALER !NOT SHOW^] 29.95 

165.95 
199.95 
SIZE: 



COUNTER WIRED, TtST^O S Cfl 
COUNTER WIHFO, lESif.O I, CBl. 



»«-!• ^ 



- ^ n 5 3 ■? 3 



L(»D««0 




3" High 

6" Wide 

5V2" Deep 

FEATURES AND SPECIFICATIONS: 

DISPLAY: 3 RED LED DIGITS A" CHARACltH HEIGHT 
GATE TIMES: 1 SECOND AND 1/10 SECOND 
PRESCALER V/ILL FIT INSIDE COUNTED CABINET 
RESOLUTION: 1 H2 AT 1 SECOND, 10 HZ AT 1/10 SECOND. 
FREQUENCr RANGE: TO HZ TO SOMH?. '65 MHZ TTfP1CAL|. 
SENSITIVITY; 10 MV RMS TO iO MHZ. IC MV FIM5 TO 63 MHZ TYP. 
INPLITIMPEDANCE: 1 MEGOHM AND 2C PF. 

■;[ODE PROTECTED INPUT FOR OVER VOLTAGE PROTECTION.! 
ACC_RACY: ^ 1 PPM"; .0001 =-!: AFTER CALIBRATION TYPICAL. 
STASILITV: WITHIN 1 PPM PER HOJR AFTER WARM UP ; OOt". XTALl 
IC PACKAGE COUNT: 3 [ALL SOCKETED] 
INTERNAL PGWEF SUPPLY: 5 V DC HEGUUATED. 
IN=UT POWER REQUIRED: 8-12 VOC OR lis VAC AT 50/60 H2. 
POWER CONSUMPTION: J WATTS 

KIT SFC-50CIS COMPLETE WITH PHEDRILLED CHASSIS ALL HARDWARE AND STgP-BY-STEP INSTRUCTIONS, 
V/IHCD i TESTED UNITS AHE CALIBRATED AND GUARANTEED. 



PLEX1GLAS CABINETS 

GreaHorClocks oranyLED 
Digital proiect- Clear-Red 
Chassis serves as Bezel to 
increase contrast of digital 
,.ABINET I disolavB 

3"H,6y4"W,5^"D Black, White or 
Clear Cover 



CABINET II 
2!^"H,5"W,4"D 



$6.50 < 



HEOORGREY PLEXIGLASFOR DIGITAL BEZELS 

rx6-.i/s- 95* ea. 4/^3 



SEE THEWOflKS Chseti Rrt 

Ci*arPI*»lgl»Slincl 



•6Biq .4" digits 
012 Of 24 hr. time 
•3 set switches 

• Plug translorme 

• a^parts included 

Plexigtas is 
Pre-cut & drilled 

KltKBSO 4CP 

Si«:6'H.4iA"W,3"D"'^^g,„b\ed 

»23^a 2/»45. ^l^^^ 



% 



Lv 



60 HZ. 

XTALTIMEBASI: 
Will enable 
Digital CiockKits 
orCIOCI^-Calendar 
Kits tooperate 
rfom 12V DC- 
r'x2' PC Board 
Power Req: 6-16V 
(2.SMA. TYP.) 
Easv 3 wire hookup 
Accuracy; ± 2PPM 
#TB-1 (Adiuslable) 
Complete Kit M95 

Wir & Cal $9.95 



SPECIAL PRICING! 

PRIME - HIGH SPEED RAM 

LOW POWER - FACTORY FRESH 

1-24 SI-T'S ea. 100-199 $1.45 ea. 
25-99 1-60 ea- 200-999. ..,1.39 ea. 

1000 AND OVER 1.29 



ea. 



S-aiBIT LED CLOCK CHLEnOHR m 



THE BUIIOER THAT WANTS THE BEST. FEATURING 12 ORIfl HOUR TIME — 

29-30-31 DAY CALENDAR. ALARM. SNOOZE AND AUX. TIMER CtRCUITS 

Wifi alternate time (8 seconds) and date {2 seconds) or may be wired for time or date display only^ 
Viiith other functions on demand. Has built-in oscillator for batterv back-up. A loud 24 hour alarm 
with a repealable 10 minute snooze alarm, alarm set & timer set indicators. Includes 110 
VAC/SOHz power pack with cord and top quality components throuoh-out-_. 



IKIT-7001BWITM6. 5' DIGITS S39.96 

|kIT - 7001C WITH A .S' DIGITS & 

2 .3 ■ DIGITSFORSECONDS - - . . S42 95 
|KIT-7001XWITH6-.6"OIGITS 545.95 

<rS AH6 COMPLETE ILESSCABINET! iki a yff^Ay ,,;, : 

ALL 7(X)1 KITS FIT CABINET : AND ACCEPT aUART2 CRYSTAL TIME BASE K.'' f TB- 



JUMBO DIGIT CLOCK 

A complete Kil (less Cabinet) featuring : 
six .5" digits, MM5314 IC 12/24 Hr. 
time, PC Boards. Transformer, Line 
Cord, Switches and ail Pafts. Ideai Fi! 
in Cabinet II 

Kit^3314-5 *19^* 2/*38. 




[BBSSaB 



Qgiseiag 



^^^ 



$Q95- 



JUMBO DIGIT AQi 

CONVERSTION KIT 5J' 
Conven small digit LED deck to large 
.5" displays. Kit includes 6 - LED's. 
Muitipiex PC Board & Hook up info. 
Ki: ffJD-lCC Fo?-Ccmmon Cathode 
Kit SJD-'CA For Cc.mmon f^naie 



PRINTED CIRCUIT BOARDS tor CT 7001 Kits 
so'd separaii- V with assembly into PCEoardsare 
drilled Fii^t-'qiass. solder Dialed and sceened 
Willi cotTi:>.Dneni layojl 



SDecply(oi7001 

B. CocX S7.S6 



iWmiE IBQ CLOCK 



AUTO BURGLAR 
ALARM KIT 

*-*EJ*Sl '■CA55EUBLi*h&E*Sf TOhH5T*^. 

ik.i^RM pHoyi:?>.c Ml.-** FtAUHE^ NO' 

pHOUlS'O^i *0^ PfiS 1 GOQ'ji^OihG 
SV(TCH(S Oft Sch&JRS .^l.L PULSE HO»H 
HEi.A* A' iHi flfsTE on anjwe Srwtn kit 

fOH EJllT EMTHV ( AIA>4M PEHiaC UNil 

mOuhts under qash HEwa'fe ^wuch 
CAS BE WOLJM'ED WnEPe :>E3ff£C CUOS 

Ht.;AaiLiTv Hisiirs f*i.sE al*bus i 

PROVIDES fUH ULTRA PePthD*ei.e H-i^AHU 
CO NQI a* fOyiiU 6T LOW PRICES' This ■& A 
TQf auAlIlT COMPLFJE kit y«ITM *LL PARIS 
inCljQiisiG DEFajuED DRAirtiHGS AND 1N- 
StfluCriONS OP AVAILABLE WIHED AND 
T£3T£D 





KIT#ALR-1 
$9.95 
#ALR-1WT 
WIRED& 
TESTED 



VARIABLE REGULATED 

1 AMP 
POWER SUPPLY KIT 

• VARIAPlE FROVI a Tg I4V 

• SHORT C RCUIT PRaoF 
1 ^23 :C REG'JLA'Ofl 

■ 2WjM5 pass -KANai5rOH 

• CL-RRcNT LIMITING At 1 Ar-^g 
KIT iS COMPLETE ISCl.VJOiNG 

DRiLi_tQ 4 sol:;fr platf.d 
FJBERGlASS PC BOARD ANO 
ALL PARTS [Less TftAMS 
FQHMERl KiTfPS-Qt Sfl.9S 
TRAKSFORMEHS^^CT will 
provide 300MA .![ iSVand 
7 AmpaiSV. S3 50 



■<l' 



r'^^^jr' DIBITS I 



12 VOLT AC or 
DC POWERED 



MODEL 
#2001 

• 6JUME0 .J ' HEO LED S BEHIND RED FILTER LeNSWirHCHROMefl.M 
- SET TIME FROPJI FRONT VIA HIDDEN SWITCHES • 12/24.Hr. TIME i 

• STYLISH CHARC0A1_ GRA.Y CASE OF MOLDED HIGH TEMP. PLASTIC 

• BRIDGE POWER INPUT CIHCUITfiV — TWO WISE NO POLAHITy MOOK-UP| 

• OPTIONAL CONNECTION TO BLANK DISPLAY lUssWfien Key Oft In Car, ETC. 

• TOP OtJALITV PC BOARDS S, COMPONENTS ■ INSTRUCTIONS. 

• MOUNTING BRACKET INCLUDED 

115 VAC ^ngQ 



KIT "2UG1 
COtVIPLETE KIT 



$2795 3 OR 



MORE 



ASSEMBLED UNITS WIRED S, TESTED 
ORDER «a001 WT [LESS 9V. BATTERYI 
Wired far 12-Hr. Op. If not ottierwise specified 



OPTOELECTRONICS, INC. 



BOX 219 HOLLYWOOD, FLA. 33022 
PHONE [3051 921-2056 / 921-4425 



03 



ORDER BY PHONE OR MAIL 
coo ORDERS WELCOME 



ORDERSTO USA & CANADA ADD H°.',: FOR SHIPPING, 
HANDLING & INSURANCE, ALL OTHERS ADD 10%. 
ADDITIONAL S1,00 CHARGE FOR ORDERS UNDER 
S15.00 - COD FEE SI, 00, FLA, RES, ADD 4% STATE 
TAX, 




lilJllUJMJtIlitlilil 



203 



D.R.C. ELECTRONICS 



1 AMP RECTIFIERS 

House Numbered. Factory 
marked units. All meet 200 
PIV minimum. Many up to 
1,000 PIV. 

30 FOR $1 

Full Leads. 



RCA HOUSE #2N3772 
NPN Power Transistor. 30 
AMP. ISO W. VCEO-60. 
TO-3. Vastly out performs 
2N3055. Reg. List S3. 04 
2 FOR $1 



OPCOA LED READOUT 

SLA-1 Common Anode. 
.33 In. character size. Tlie 
original high efficiency 
LED dispiay. 
$.75 each 4 FOR $2.50 



PRECISION 
RESISTORS 

IK OHM 1% 

10KOHM1% 

Your Choice: 

6 FOR $1 



MOTOROLA CD 4040 

ClVfOS 12 Stage Binary 
Ripple Through Counter. 

S .99 ea. 



CALCULATOR 
DISPLAYS 

Brand New Units 

By BOWMAR. 

Common Cathode. 

.11 INCH CHARACTER. 

9 DIGIT - $ .99 

6 DIGIT ■ $ .69 



MYLAR CAPACITOR 

1 .MFD. 400 VDC. 5% 
2 FOR $1 



THERMISTOR 

1 K OHM at Room Temp, 

Very .Sensitive, 

4 FOR SI 



741C OP AMPS 

MINI DIP. Prime New 

Units, Has computer 

MFG's house number. 

12 FOR S2 

100 FOR $15 



DISC CAPACITORS 

.1 MFD 16 V. P.C. Leads 

Most Popular Value! 

P.C. Leads. By Sprague. 

20 FOR $1 



HEAVY DUTY 
FuU Wave Bridge 

25 AMP 50 PIV 
$1.25 



POWER RESISTORS 

.5 OHM 50 WATT. 

Adjustable ■ 5% 

2 FOR SI 



3 OHM 15 WATT. 5% 
3 FOR SI 



.25 OHM 
3 WATT. 1%IRC 

4 FOR SI 



POWER ZENER 

IN3998A 10 W. 6.2 V. 
2 FOR SI W/HDWR 



16 PIN IC SOCKETS 

Low profile. Solder Tail. 
5 FOR SI 



ZENERS 

1 W. 15 V. 

House Number. 

Motorola. 

5 FOR SI 



TANTALUM CAPACITOR 

1 MFD. 35 V. Kemet. 

Axial Lead. Best Value. 

10 FOR $1 



MISC. SEMICONDUCTORS 

709C Op Amp. ITT S .29 
14 Pin Dip 

IN4004 lA. 400 PIV. L R. 12/$1 

2N2646 Mot. Unijunction 2/Sl 

2N4871 Mot. TO-92-Unij. 3/$l 

2N3819 T. I. House #N-FET. 4/$l 

EN3906 PNP Driver XSTR 10/Sl 

LM565 Phase Locked Loop $ .99 

LM723C V. R. 14 Pin Dip $ .79 

4136 Quad Op Amp S .99 

2N5777 Photo Transistor 5/$ I 

1N4748 1 W. 22V Zener 10/$1 

2N2925 Pre-amp NPN XSTR 8/$l 

2N1307 PNP Gennanium 5/$l 

EN2222 House # XSTR 10/SI 

2N2219 TO-5 NPN Power 4/$l 

1N5384 5W 150V Zener 5/$l 

TIS92 NPN Driver 10/$ 1 



TRANSFORMER^ 

12 Vac. 600 MA. 
PRI— 115 VAC 60 HZ. 
Perfect for clocks or power supplies. 
^ -'■■ Small Size. 



$1.95 



JUMBO LED READOUT ARRAY 

By Bowmar. .5 in. char, 
common cathode. Designed 
for use with multiplexed 
clock chips. Four digits in 
one pack. 

LIMITED STOCK 



nTTf?mtttttt 



CABLE TIES 

Most popular size. 3V'," overall for "a'-Vt" 

bundle. Ty-wrap style. Nylon self-locking. 

100 FOR $1 S8 FOR 1,000 



$1.95 



FILTER CAP 4 FOR $i 

Miiii Size. Axial. 1,000 MFD 16 WVDC 



HEAVY DUTY 115 VAC RELAY 

By Guardian. Coil is 115 VAC 60 ,^ 
HZ. DPDT 10 AMP Contacts. 

$1.95 each 




TRANS 



2N3566 - TO - 5 plastic. NPN. 

VCEO-40 HFE 150 TO 600 

10 FOR Si 



STORS 

MPS-6566 - TO - 92 

plastic. NPN. 

VCEO-45 HFE 100 TO 400 

10 FOR $1 



RED LED READOUT FILTER 

Very handy. Can- be used with 

our Calculator Displays. 

21/4 X y. in, 6 FOR $1 



CINCH-JONES 
S TERMINAL BLOCKS 

Q ?f5-140 5-Termina! — 3 FOB SI 

Eg |!i!9-140 9-T'-,r.-ninal"2FORSl 

5-140 is 2.5 !;i, 9-140 is 4 In. 




ROTARY 
SWITCH 

Instrument Grade, 

3 Pole. 

6 Position, 

Centralab. 



99c 



TERMS: ORDERS UNDER $15 ADD S .75. NO C.O.D. WE ACCEPT VISA, MASTER CHARGE AND AMERICAN 
EXPRESS CARDS. MONEY BACK GUARANTEE ON ALL ITEMS. TEXAS RESIDENTS ADD 5% SALES TAX. 



WC^ 



WE PAY POSTAGE! 
ELECTRONICS P, O. box 401247 • garland, TEXAS 75040 • (214) 27 1-2461 



D20 



204 



D.R.C. ELECTRONICS 



16K E-PROM CARD 

S-IOO( IMSAI/ALTAIR) BUSS COMPATIBLE 



$69.95 (KIT) 

IMAGINE HAVING 16K 
OF SOFTWARE ON LINE AT ALL TIME! 
KIT FEATURES: 

1. Double sided PC Board with solder mask and silk screen and 
Gold plated contact fingers. 

2. Selectable wait states. /" USES 

3. All address lines and data lines buffered! 

4. All sockets included. 

5. On card rcgulator.s. 

KIT INCLUDES ALL PABTS AND SOCKETS! (EXCEPT 2708' s) 

ADD S25 FOR 
SPECLA.L OFFER: Our 2708's (650 NS) are S12.9S when purchased with above kit. ASSEMBLED AND TESTED 





DEALER INQUIRES INVITED 



$149.00 KIT 



8K LOW POWER RAM KIT! 



ADD $30 FOR ASSEMBLED AND TESTED. KIT FEATURES: 

1 . Double sided PC Board with solder mask and silk screen layout. 
Gold plated contact tnieers. 

All sockets included! ^ S-1 00 (IMSAl/ALTAJR) 

Fully buffered on all address and data lines. PUSS COMPATIBLE 
Phantom is jumper selectable to pin 67. 
FOUR 7805 regulators are provided on card. 




USES 
21L02-1 
RAM'S. 




S-100 



REVERSING 

EXTENDER BOARD 

$24.95 Turns the board under test around so that the foil side is facing you. 

with connector Makes trouble shooting and debugging a SNAP! P.C. Layou"!" designed to 

niinimize noi^e atid stray capacitance. 



■M TTiiiiirrnrTT 



COMPUTER GRADE CAP. 

48,000 MFD 25 WVDC Mallory 

$3.95 NEW! 



T. I. ASCII CHARACTER GENERATOR 

IMS 4103 JC. 28 PIN CER DIP. Has 

seven bit COLUMN Output for use with 

Matrix hard copy devices. With specs. 

'S3.50 



IC SOCKETS 

For the newer RAM chips. 

18 PIN — 4 FOR $1 

22 PIN — 3 FOR Si 



RCA HOUSE nmn2 

NPN PQwcr Transistor. 30 AMP. 

150 W. VCEO-60. TO-3. Vastly out 

performs 2N3055. Reg. List $3.04 

2 FOR SI 



^E^- 4K STATIC RAM ^S '^^H'; 

2114. The industry standard- 18 PIN DIP. Arranged as IK X 4. Equivalent to 

FOUR 21L02's in ONE package! TWO chips give IK X 8, with data. 

2 FOR S24 

450N.S.! 



MOTOROLA 7805R 
VOLTAGE REGULATOR 

Same as standard 7805 except 750 MA 

OUTPUT. TO-220. 5VDC OUTPUT. 

S .44 each 10 FOR S3. 95 



NATIONAL SEMI. MA1003 CAR CLOCK 

Not a kit. Complete tested module. 
Works on 12 VDC, has on board time 
base. Sold by others at 524.95. Big .30" 
Bright Green Digits. Same as used bv 
Detroit in new cards. 






$19.95 



EDGE CONNECTOR — SI. SO 



Z - 80 PROGRAMMING MANUAL 

By MOSTEK, the major 2 - 80 second source. The most detailed explanation 
ever on the workings of the 2 - 80 CPU CHIPS. At least one full page on each 
of the 158 Z - 80 instructions. A MUST reference manual for any user of the 
Z - 80. 300 pages. Just off the press! A D.R.C. exclusive! ^ 2.95 



IKX8 
2708 EPROMS 2708 

Prime new units from a major U.S. nifg. 
650 N.S. access time. Equivalent to four 
l702A's in one package! 
$15.75 ^h 



TERMS: ORDERS UNDER $15 ADD $ .75. NO C.O.D. WE ACCEPT VISA, MASTER CHARGE AND AMERICAN 
EXPRESS CARDS. MONEY BACK GUARANTEE ON ALL ITEMS. TEXAS RESIDENTS ADD 5% SALES TAX. 



>^ ^^ 



D20 



ELECTRONICS p o box 40 1 247 



WE PAY POSTAGE! 

GARLAND. TEXAS 75040 •(2)4)271 -246 1 



*•••• ••••••••••*•••••••• •••••••*••••• ••••••••••••^ 

■fC CLOCK SPECIAL GOOD 
jj THROUGH DEC. 31sC. 




Grandson ot 

a Cheap dock 




CLOCK SPECIAL GOOD j^. 
THROUGH DEC. 3ist. ^ 



♦ *■¥-¥ 



plus 
1 lb. post 






tAYE 



Several years 3£Oj we iT^Trnduced our "CTioap CLock", a siKiple^ unpretentious clock kit that has spawned nu- 
merous iTnitations- Later, we upgraded our kit with bigger readouts, brighter digits^ and a tigger board; 

that was our "Son of a Cheap Clock'". Our current clock is t'ne ^'Grandson of a Cheap Clock'^ and this time 

we have upped the digit size to .4", while retaining all the 1-eatures that made the original clocks such 
big successes ... like 6 digit operation, sejiarate drivor and segjuent transistors, 12/2^ hour operation, 60 
or 50 Hz capability, industrial quality PC board, IC socket to clirainate he-at dasiage, and so on. 

This is a complete clock kit... less only case, 
board and transforaisr, we include both itesis 
Oar data sheet tells hoiv to renote the reado^iLS 
eratiOHj and assembly procedure. 



'Jnlikc ir^any of our iT^sitators i^'ho charge extra for the PC 

--as well as tiir.c setting switches iv. the package price. 

hov." CO use witK a tine base for battezy or autonotive op- 



ife«i i^ 



4- i. 



H.-.- 



SVr 



fi I 






M" 



^1,000 

$4.95 25V 



ul 



000 uR 

' 25V y 

$5.95\4-IOOKpots 



CMOS 



4000 


S0.2S 


4057 


0.50 


40G1 


0.29 


4040 


l.SO 


<1C02 


0.34 


4041 


0.S5 


4007 


0.29 


4042 


fl.SS 


4008 


1,28 


4043 


0.60 


4009 


0,S3 


4044 


0.60 


4010 


0.53 


4047 


1.<J3 


4011 


0.29 


4049 


0.50 


4012 


0.29 


40S0 


O.SO 


4013 


O.SO 


4QS1 


1.03 


4014 


1.25 


40S2 


1.03 


4DIS 


0.90 


40S5 


1.03 


4016 


0.45 


4 060 


1.4S 


4017 


1.23 


4066 


O.SS 


4019 


0.5S 


4Q69B/ 




4020 


1-SO 


74C04 


0.33 


4021 


1.23 


4070 


0.60 


4022 


1.20 


4071 


0.33 


4023 


0.29 


4073 


0.35 


4024 


1.03 


4075 


0.33 


4025 


0.29 


4076B/ 




4027 


0.7S 


74C173 


1.63 


402S 


1.00 


4081 


0.33 


4029 


1.73 


4116 


0.50 


4050 


0.53 


14511 


2.00 


4033 


1.50 







New from VECTOR.. 

W2 ASSEJ1BLE0 HICROCOHPITTER CASE... an 

adjustable packaging system for S-IOD 
buss microcomputers. Card guided and 
hardware for 12 cards, with provision 
for 21 cards total on .75" centers. 
Irtstantly access ible mteriors with 
slip out covers; sturdy chassis plate 
for power supply- And.,^it'5 really 
b**utiful $134, >0 

Personal to Fratik Tinius : wacch 
this space, it's happening I 



8Kx8 
Econoram II 

single kit $163.84 
3kits-24K!-$450 




Those who know rrKnory recognize the Godbout board 
as not just an exceptional value (it's no secret 
we know how to keep co^ts down), but as an example 
of how to p^ck extra options into a basic memory 
board. Extras like a vector interrupt provision 
if you try to write Irtto protected memory. Con- 
figuration as two independent ^K blocks {both pro- 
tectable se para tely) . A selectable write strobe 
for either PUR or MURITE. An all static design. 
The ability to handle D.1A devices. Suaranteed 

speed under kSO ns (witn on-board wait state logic 
for use v/i tn 4 MHz Z-80) and guaranteed current 
under 1 . 5A (1250 mA typ) . And of course. .. sockets 
for all ICSj legended board with solder mask, one 
^year warranty on parts .. .we 've got It aH 

ALSO AVAILABLE: 3K ASSEMBLED, TESTED, UAFtRAN 
TED 1 YEAR. ..Si &8- 50; kK KIT. ..5100 



TERMS; Please allow up to 5t £ot ship- 
ping, more for supply & VP2; excess re- 
funded. Prices good through end of maij- 
azine cover i:ionth . Californians add tax. 
CODs accepted with street address. Tor 
Bank Atnericai'd /VISA /^]ast ercha rge*^ ord er s 
C$15 min) call 415-562-0636, 24 hours. 

206 




BILL GODBOUT ELECTRONICS 
BOX 2355. a^KLA^ID AIRPORT CA 9461-1 



Low power Schottky 




74LS00 


SC.30 


74LS151 


?0.95 


74LS01 


C.30 


74LSi55 


1.38 


74LS02 


0.30 


74LS157 


0.95 


74LS04 


0.33 


74LS160 


1.40 


74LS08" 


-■ 0.36 


74LS161 


1.40 


74LS10 


0.30 


74LS162 


1.40 


74LS11 


0.36 


74LS163 


1.40 


74LS12 


0.33 


74LS16S 


1.S7 


74LS14 


1.38 


74LS15S.- 


1.37 


74LS15 


0.30 


74LS173 


1.65 


74LS20 


0.30 


74LS174 


1.25 


74LS21 


"■" 0.33 


74LS175 


1.15 


74LS22 


0.33 


74LS195 


1,30 


74LE26 


0.43 


74Ly240 


1-88 


74LS27 


0.36 


74LS257 


1.25 


74LS30 


0.30 


74LS258 


1.25 


74LS32 


0.38 


74LS266 


0.53 


74LS37 


0.45 


74LS283 


1.20 


74LS38 


0.45 


74LS365/ 




7i.LS42 


0.98*- 80LS95 


0.75 


74LS47 


1-00 


74LS366/ 




74LS4S 


0.98 


30LS96 


0.75 


74LS74 


0.5O 


74LS367/ 




74LS75 


0.68 


■ S0LS97 


0.75 


74LS76 


0.50 


74LS358/ 




74LS86 


0.50 


80LS98 


0.75 


74LS109 


0.50 


74LS386 


0.55 


74LS125 


0.63 


81LS95 


1.13 


74LS126 


0.63 


811S96 


1.13 


74LS132 


1.25 


811S97 


1.13 


74L313S 


1.10 


81LS98 


1.13 


74LS139 


1.15 






lOSlot 


Motherboard 


$90 


18 Slot Mother 


board 


$124 




Both have edge connectors » active terminations 

CPU POWER SDPPLY S50 

5V a 4A, tl2V 5 iiA, -12V J !iA. Kith crowbar, 

SEVERAL GOOD REASONS HHT VOU SHOULD 
HAVE OUR FLYER: 1) CMOS 2) LINSARS 
j) MICROPROCESSORS 4) POWER SUPPLIES 
5) RESISTORS 6;i CAPACITORS 7] DIS- 
PLAYS 8) SOCKETS 9) VECTOR PRODUCTS 
10) ENCLOSURES 11) ALL THE OTHER 
THINGS WE CAN'T FIT INTO THIS SPACE. 

G4 



y^iP»7400fTTTL 



WIRE WRAP CENTER 

HOflBY-WfWP TOOL-BW- 

BsBe.-y OjjersteO jSM C) 




207 




High qunlrty sockets far 'C's arid PC inter<:oTne<^fions. 
Check o\rr pnces nnd qua\}\y- you wfH see v/Jiy TRl-TEK 
ii fcist becommg the leader in IC sockets. 

Lovv Profile 3'? Saicer to', "i-; 
Etid /Sld^ sTOci^able an ,100' tenrers 

1^9 la--24 25-100 



SKT-0802 8 Din 


.15 


.15 


.14 


1402 IJr.ir 


.18 


.17 


.16 


I4D2 lipln 


.20 


.19 


.13 


ISD2 Ifipln 


.27 


.26 


.25 


2Q02 20pin 


.25 


.28 


,27 


2Z02 22pm 


.35 


.34 


.33 


2402 24pin 


.36 


.35 


.34 


2302 2epin 


.■12 


.41 


.40 


^.CK:2 «)pin 


.i-3 


.57 


.53 



3 UvbI Wire Wrap Cold 



S<--I4-M 
1603 



24O0 



1-9 
,33 
.42 
.73 
1. 00 



10-24 
.37 



4000 1.69 i.SI 



.40 
.59 
.S3 
1.37 




EiEBON CAiJLE !C I NTEBCONMSCrs 



12" 



18" 



14P ■ 1.51 

16P 1.64 

24P 2,49 

14P 2.76 

I6P 3,01 

24P 4.55 



1,62 5.72 

'.76 ;.e7 

2.69 2.98 
DOUBLE EN D 

2.87 2.97 

3,13 3,24 

4.75 4.54 



24" 
1.B3 
1.59 
3. OS 

3.03 
3.36 
5.14 



36" 
2,05 
2,21 
3.4a 

3,30 

3.sa 

5. 54 



48" 
2,26 
2,44 
3.B7 

3,51 
3.ai 
5.93 



«: 



yXj^ ^. ft 200 Volf, 30 Amp BRIDGE 

zL* r^'rvj *^(^ H? current bridge in rech^ 

t^ aroLijci' caie. Has tnlegral 
hajt rrcKfer disc fo: bs5i 
ccaliro. An nvsrsTock sT c 
^. la."3ii eqjipmefit m3rii,rocr^ 

urer brings you a bargain 
from a famous Sumi^Conductor nionufaclurer ...... n , . 

B[iK-2230.Vi S2.00 



fe.:^-^; 



Ldching Reed Rela/ 

Viiniafore reed reio/ wJlh 2 colls and latching '■eed. 
Use one coil tCt set. Other to reset or reverse eurrenf 
in one coil for opposite funcHors. Single pole- 
sincle Throiv cciprule. P,C, MounHng. Rated ot 
13.5V hjf w«ks grear on I2V " 
RYL-I201C, A^l'^^dfl^H -^^'^5 





G.E, PANEL mete;? 

Altrcct?ve rectcncsylor meter hixv. G.E.'s 

HORIZONTAL LINE, Mocel -it:)-15701 1 , 

to 20V scale. 2-2" ocross face. 2 hale 

mount. Catologs for more than S20. 

Brand new in boj^es wHh hardware. HOBrz*H 

G^0VM^j^^^^^^^^^^^^^^^^l2^^^ 

J^ WfT NICAD CELLS 

1,2V cells in transparent j-ect-anguiar ploslic 
I cose. Removed from equipment bur O.K^ 
j Juit [idd disHlted water ond chgrgc. 
I Two jizej to chose Uz— , 

I 1,5 Amp HoLr ,..., ,52,20 

I 2,GAmpHotjr 52.69 

Popular import germanium paV/fir Irarlsistor m TO-66 
Used m many Imported tape and record ployeri, etc. 
2S&367... ..$1.50 



inrnr 



Soys 



ji. 

Here we ^row og<;ri>! We're moving 
into oyr new locoticKi to sarve you 
i>etler. CheK.t our new cddre^i and 
telephone nunjber» 
Thanx for helping us grov/! I I ! ] [ i i 



MRF475 



NPN SlLiCON RF POWER TRANSISTOR 



, . . , ,(ieiigned prininrlly for u^e in sirtcle sidetand linear QTiplifler 
outpi,-: appiicQtisns in citizens ocnd and other comTi on i cations equfp- 
menf cpercrlfng to 30 MHz, 

O Choracterized for Single Sidebcjnd and Lorge-Signal Amplifier 
Signal A:r.plifie- 
Applicotioni Utilizing Lov.— Levef l/adulatio.T 



O Specified 13,6 V, 30MKz Characteri&fics 
Output Powers 12 W (PEP) 
Minimum Efficiency ^ 40% (SSB) 
Ojtsut F3wer ^ 4.0 W (OV) 
MiriijT.Lm Efficiency ~ 50^-'s (OVJ 
Mi^tT^«=j ?&wer Gain ^ 10 dS JpEP S. ON) 



^' 




• ^ 


Wjong 




Lfj.1i . 




■ -J-ri^f 


■^rao ^S 


. J^-.^,M 


..VirL ^^: 


i-jc 1 




-:^ 1 _^^, _ 


^1 


, !'." ''.' '■''''"' '^ 


'^■^■"i; '' ''J 



Direct replacemenr for 2SCI969 for irnptirted radio 

y.K?-^7S 54 > 3 2 



2N530' Sj=er Tranny 

200VV 40V 30A NPN siMcon tran^israr in TO-3, Per^cr for Power 

Supply pass clement. Mcda by Motoroia Far giant computer compony 

who over stocked thsm - your gam, 

2N530I {House Mcr^}. , SI , 25 



Hi Voitoge Hi ?&jver NPN 

G .E. D56W1 is Q I4C0V, 5A NPN transistor in TO-3 case, Ued In 

Hurizantai deflecl^iori driver for color T.V. or any hi voltage hi pulse 

energy applicotJors. 

D56Wi S2,^ 




^ 



MM74C935-1 

3^ digit DVM wrth muttiplfixMl 7-sasment oirtput 




The MM74C93S Monolithic DVM circuit is manufac+urod 
using standard ccmplementory MOS(CMOS) lechnolagy, 
A pjise madubticn cncjiog-lo-digital conversion techni- 
que is usea era requires no exfcnnl precision csrrrpsn- 
enfs. in ccdiltoiir fhis tecj^nique allov/s the use of a 
reference voltage fho: 15 the soitt? poiority as the input 
voltage, 

O^.c 5V(TTL] power iupply is required. Operotinc v/lth 
an isol^tec SJppiy allnw) irte conve^'Slo.^ of positive ai 
well Qi negative vollo^es. The sign of the input voliase 
I^ GUtomatically dsterTi.ined end outpu; 30 the sigji pin. 
If the pavJEi supply is not isolated, only one polarity oF 
voltage may bu converted. 

The: coTivET^ion rnfe is set by an ifbternal Mcliiator. Tr^e 
frequency of the cscl^lotor con be set by cr external KC 
netv/arn; or the osciilator can b-e driven from an extecfVol 
frequOncj: sourcH, When using the external RC nehvork, 
a square wave ojtpjt Is available, H is important to 
note that great core haj been tokan to synchronize diyit 
:7.!jitiolexing with the fi/D codvarsi&n tirriing to elimi- 
nate noise due to power supply transients. 

The MM74C935 has bsen designed to drive 7-segment 
muJtipleKed LED displays dirpcHy with the aid of 
extemo! digiJ buffers end segrricnt resistor. Under 
condition o? oven-ange, the ove^How oytpjt will go high 
5nd the display will re^d -KDFL cr -OFL, dependirg on 
whether"Vhe input voltage is positive or negative. In 
ffddi+ion to fhij, the most significont digit is blanked 
v/hen lero. 

A storr ccnverslcn Input end o conversion complete 
output ere included 
FEATURES:. 
O Opeates From single 5V supply 
O Con'/ertsOV+o +I,9??V 
O //.uJtiplexed 7-segment 
O Drives ieamen'j dlr^rtly 
O No external precisicn compcnent necessary 
O Medium :;peed ^ 200iiis/con version 
O All inputs and outputs TTL compatible 
O internal clock set with RC network or driven 

e>:terna[l/ ■=« 
O No offset cdjus! reqjlred 

C Overrange indicated ty * OFL or -OfL display 
reading and OFUO oi/hpuf 

Analog inputs in applications shown can withstand 
IZDO Voltl; 



O 



APPLICATIONS: 
O \.ow cost digital pov/er supply readouts 
O Low Costdigltai multimeters 
O Lov/ cost digital pare/ meters 
O Eiiminctc anclog multlplcwrLS ^y using remote ^/D 

converters 
O Convert analog trcnsduc«r5 (temperofur^^ pressure^ 

displacament, etc = } to digital transducers 

MM74C935N-1 , .wi th ipecs „ , Si 6.9S 

Specs only for 74C935 5.90 

I_M336Z Re'crerjte eiode 

Precision 2V reference to oe used with MM74C935-I 

DVM chip. 

LV,336Z 52.40 




tRi-tek, inc. 

7803 N. 27TH AVENUE 
PHOENIX, ARIZONA 85D21 




We pay 5Lifface shippinc on all orders over SIO US, SI5 foreign in US funds. 

Please add extra for first c\c3i.i. cr air moil , Excess will be refunded, Crcers 
under SIO, odd $1 handling. Please add 5(}i; fnsurance. Moster charge end 
Bank America cards welcome, ($20 minimum). Telephone orders moy be 
ploced lOAM to 5:3D?M daily. Mot. thru Fri. Coll (602) 995-9352- 

C^eck reader service card or send stomp fcs" our btest fiyers 
packed with neyj or.6 s^gplus electronic component!;. 



ALDELCO ELECTRONIC CENTER NOW OPENI 

Kits, Books, Boards, Magazines. Special 2102LI 6 for $17.50. 8080A CPU Chip $19.95. We stock OK Battery Operated Wire Too! 
$34.95, OK Hand Wire Wrapped Tool $5.95. 7400 ICs CMOS. Timers PLL's IC Sockets. All kinds of transistors, rectifiers and diodes. Plus 
other electroriic parts. 

Add 5% for shipping. Add $1.00 for order under $10.00. Out of U.S.A. send certified check or money order, include shipping costn. 

BUILD THE W7BBX PROGRAMMABLE KEYER. SOLID STATE PARTS WITH IC SOCKETS $42.00. V/E CAN StJPPLY THE FOUR PC 
BOARDS AND COMPREHENSIVE CONSTRUCTION MANUAL - ALL FOR ONLY $29.95. 



National iVIA1003 




Actual Size — 1 .75" x 3.05" 



BRIGHT .3 FLUORESCENT DISPLAY 

Same unit supplied as original equipment in many new auto- 
mobiles • 12 volt DC • Xtal timebaSR • 12 hour format • 
completslv assembled unit •dims to comfortable viewing ■Jihen 
car lights are on • low standby power consumption. 

All for ONLY S24. 95 



PLUS - FREE 

3 pusii switches and choice of green, 
blue or amber filter. 

also good for marine and aircraft 



lOQ' Spoal Green =30 wire 

Wrap Wire S2,75 

OK Wire Hand Too> 

WSU 3Q 5.95 

WSU3DM (moditiedwrap) . 6.95 
Battery operated wire-wrap tool 
BW63a Wraps #-30 wire 34.95 
New! Model BW 2628. Wraps 

S26 + -28wire S39.95 

Batteries not included. 

• RECTIFIERS 
2 amp 50 volt 20 for $1.00 
2 amp 1000 volllOforSI.OO 
2 amp 1500 volt , 5 for 1.00 

6 amp 1CX) volt 69 

10 amp stud 50 volt . . 1.50 
10 amp stud 600 volt . 4.50 
40 amp stud 50 volt . . 1.20 
40 amp stud 750 volt . 2.05 
BRIDGES 

2 amp T05 50 volt 35 

2 amp T05 200 volt 50 

2 amp T05 600 volt . . 1.25 



3 amp. 50 voit 
3 amp. 400 volt . 
25 amp. 200 volt 
25 amp. 600 volt 
25 amp. 1000 voit 

VOLTAGE REGULATORS 
T0220 Package Si .00 each 



. .50 
1.10 
1.50 
5.50 
8.50 



Positive 

7805 

7306 

730B 

7812 

7815 



Negative 

7905 

7906 

7912 

7915 

7918 



LM30BHTO5 SLID 

LIVI3D9KT03 1.10 

LIVI72314pin 55 

• FETS 

40673 1.55 

MPF1G2 55 

2W3819 35 

2f\l5457 50 

2M5458 50 

2N5459 55 

2N5485 50 

• DARLINGTON 

IVIPSA 13 80 

MPSA 14 4Q 

2N5306 50 

• SCR 

C106A 55 

C 106B 65 

CI 228 85 



LOGIC PROBE KIT 
Aldeico is new the sale 
distributor of the 
DIGAPEAKE - a logic 
probe kit. Now you can 
buy direct and save. Probe 
measures logic 1, logic Q, 
and pulsing circuits coo- 
ditions formerly sold far 
SI4.95. 

SPECIAL S!1.B5 

ACCUKEYERKIT Sim- 
ilar to the famous ARRL 
Handbook version. Kit 
includes PC board, IC 
sockets, ICs, speaker 
switch and all parts and 
instructions. 

ONLY $19.95 

ACCUKEYER 
iVIEWiORYKIT 

Adaptsble to many keyers. 
Can store 2 canned 
messages of 30 characters 
eacli. PC hoard IC sockets. 
ICs instructions and all 
parts. S19.95 

CLOCK CHIPS 

5313 

5314 

5316 

5375 



2ENERS 



3.49 

3.39 

3.95 

3.95 

CT7001 6.95 



ii?<G:n vr;Jb9 . , 4t(i >.v, s: JS 


>.>4)38lri!MI6i 1 Ml! 


2S 


riB3j3io lNi3?8 5n6ii 


2 ;i) 


•J237Dl5!t43(i05 10 MI 


... 2 40 


>l33tiS[o lN3jaO 50 MI 


4.75 


ALZ1S(GE 2!M 


S4 50 


AL 216IGt 2161 


7.95 


ZN30SS 


. 99 


2N3904or ZNJaOG . 


25 


2N549BIJI 2W6IOe .. 


70 


MJE340'2N5Bb51 . . 


.. . 1.1(3 


741 :■■ 1^0 J 14 P.- J:P 


25 


izb T -I". 


.49 


5:6 D.jii 555 


■,so 


-r,?i: ;:,;-;8 


...::■; m 


i\j41f.5- --.S^ 


.. -0 1; 3S 


CA 3028 DM Am: . 


.... liB 


4j5: CMC; 


3.00 


:.',;03K V;:l RS3 


IID 


r.:j3055 


. . 2 W 


2i55o: [:'-s rmeiL: 


S3 


?i0333 


20 


B2SZ3 


3.95 


2r<6;[i3 . .. 


.... S8 


LM70g or 74! t^in DIP Op Anm 45 


LM741CE T05 Op Amp . 


45 


14 01 16 Pin ICSockti! ,. 


30 


RF DEVICES 


2M3375 3',".400KHr 


S: 50 


Z'iiiSBS).'. 4i)I)l.'Hi 


t 15 


2'46=S3:','. JiKH: 


J 75 


2H;53a"S( 175 V't 


7.80 


lmb?1 i'AI |J5 W>-f 


;o.9i 


2SC517 


3 35 


ISCVi26 


1.25 


JfioOgnin WSHii: 


5.4D 


JriMBl ■•%■! l!5UHi 


8 46 


JkBOB! jW l)5Mttj 


10.95 


2k6(133 3(M- m»»i 


I2.3(i 


2NB0e4 40i',' l!5MH! 


IB 30 


2SC1306 


. r. 30 


2SC1303 


,. . 6,2S 


2W2B3B 


-. sptuial 10 95 



ALDELCO KITS 



• NEW IMPROVED 
ALARIVl CLOCK KIT 

Digital alarm clock • Six big .5 display lEDs 

• New on board AC Transformer • 12 Hour 
format v.fith 2A hour Alarm • Snooze 
Feature • Elapsed tinie indicator. 

A natural for cars, campers and mobils 
homes. Use on 12 volt dc vJitti optional 
crystal time tjase (not including cabineti 

S19.95 

• CRYSTAL TIME BASE KIT $4.95 

Optional cabinet - in simulated walnut grain 

or black leather $4.95 

Plastic cabinets — blue, black, white or smoke 

S3 .9 5 

Red clock filters S-60 

12 or 24 hour DIGITAL CLOCK KIT uses .5 
display LED. 52^^ clock chip fits uur stan- 
dard cabinet. Freeze feature SIS. 95 

Blinky Flasher Kit 

PC 3Mrd, 555 & all parts works on 9 volts — 
$2.50. Morse button - Sl.OO. 




2 Dual Digital 
12-2a hour clock kits 

n/lQOEL ALD5: 

Six big .5 ditplav LED; in an attractive black plastic cabinet with a tea 

frgnl filtBr. Great for a ham or broadcaft Station. Set one ClOCk to GMT 

the oth.w tfl leiESl tima_ Or have a 3d hour format on one cloch and 12 

hour on the other. Freeze fsaiuf« lun the clock be 3el to thei*ajnd. 

Each clotk IS controlled sep^ratuly. Cabinet maaame^ ?'/*" K 4V K 

9;s".ComplirtB KilS44.95. 

r/OOEL ALD7: 

Four bright .3 nixie lube display. CabinM is an atrranive d««p blue 

incluairi9 tror^i fitter. Will di^plav lecooils at the push at a bullon. An 

aiiset to anv station. Cabinet size n 2Ii" x 3" % 914". CoropfelB Kit 

S34,95. 



Variable Power 
Supply Kit 




-500 mA reaulato7s'feature 
current linniting and 
tfiermal protection. 



Specify: 

5 to 16 Volt 

or 

12 to 28 Volt 

unit 



only $6.95 plus $1 .00 shipping 

AWelco presents a *s>1 IP \i# 

Frequency Counter and digital clock kit in one cabinet 



12 3r 24 hour 

digital deck 

Sis .3 display LEDS 



Frequency ix^ufiTer 

lyptel 100 Hz to 10 MHz 

accuracy .0001% 



SwiTchable from counter to clock. Clock maintains tinne 
while frequency counter is in use. Can be wireci for either 4 
or 6 digit clock. Small si^e makes attractive unit for auto or 
boat. Operates on 12 volt DC. Plug in power supply is 
available for 110 volt AC use. Comes complete with 
instructions. Cabinet and all parts assembled unit . . . 

S1 39,95. Optional 110 volt AC supply S5.9S 

Kit only S99.95 

Frequency counter kit with memory similar to above but 
without digital clock - $99.95. 

Assembled unit $1 39,95 

110 V ac power supply $5.95 



ALDELCO 



2281A BABYLON TURNPIKE, MERRICK NY 11566 
516-378-4555 



A2 

Meet us at ths Clearwater FL Convention November 18 & 19. 



209 




SD SALES COMPANY 



P.O. BOX 28810-A 



DALLAS, TEXAS 75228 



NDW-THE ULTIMATE RAM BOARD 
32K FOR $427. 



Memory Capacity 

Memory Addressing 

Memory Write Protection 

8K, 16K,2'iK, 32K USING P.10STEK iViK'l 115 
WITH 8K BOUNDARIES & PROTECTION". 
Utilizes DIP switches- 
PC board comes with sockets for 32K operation 
THE ABOVE NOW AVAILABLE 



■AVAILABLE THE 1st QUARTER OF 1373:* 
13K, 32K. 48K, 6-lK USING MOSTEK 4116 
WITH 16K BOU\DARiES& PROTECTION. 



BUY AN SlOO COMPATIBLE 8K RAM BOARD AND UPGRADE 
THE SAME BOARD TO A MAXIMUM OF 32K* IN STEPS Or 
8K AT YOUR OPTION BY MERELY PURCHASING 1«0RE 
RAM CHIPS FFIOM S.D. SALES! AT A GUARANTEED PRICE^ 
LOOK AT THE FEATURES WE HAVE BUILT INTO THE 
BOARD- 

PRLCES START AT S139.00 FOR 8K RAM KIT. 
ADD $96.00 FOR EACH ADDITIONAL 8K RAM DESIRED 

Baard fully asseinbled and tested fof S50.00 extra. 

BK FOR $139. 



Interface Capability 

CONTROL DATA AND ADDRESS INPUTS 
UTiLlZE LOW POWER SCHOTTKY DEVICES. 

Power Requirements 

tSVDC 400 MA DC 
+ 18VDC 400MA DC 
-18V DC 30MA DC 
on bosrd regulation is provided. 
ON BOARD (INVISIBLE) REFRESH IS PRO- 
VIDED Wru \10 IVAI7 STATES OR CYCLE 
STEALING REQUIRED. 

VEfslORY .ACCESS TIME IS 375ns. 
Meirory Cycle Time is 500ns. 



Z-80 CPU BOARD KIT complete Kit 

$139. 



CHECK THE ADVAI>JCED FEATURES OF OUR Z-80 CPU BOARD 
E>(panded set of 158 instfijctions, 8080A softtvsre capabiiiiv, operation from a single 
5V0C power SLpply, always stops on an Ml state, true sy ic generated on card (a real 
Plus feature), dynamic refreshi end NMI available, either 2rif!HZ or 4MHZ ofieraiion. 
quality doubia sided plated lhroJg^l PC board, standard kit sf.ipped vfttn Z-80 technicaJ 
manuaJ and all parts plus sockets orovided for all IC'S. Z-BOCr^in & \^anual Sep. - 39.95 
•Add $10.00 extra for Z—SOA chip which a!:o'/js4MHZ operation 



4K LOW POWER RAM 

Fully Buffered — on board regulated - reduced power 
consi/mtion utilising low power 21L02— 1 500ns RAMS — 
Sockets provided for aH IC's. Quality plareci through PC 
baa'a. 'Add S10-00 ior 250ns RAM operation. 

The Whole Works - $79.95 

NEW PRICE! 



ALL OF ABOVE ARE S100, IMSAI & ALTAIR 'A' COMPATIBLE. 
We can supply modifications needed for many other systems! 



SIX DIGIT ALARM 
CLOCK KIT 

FEATURES; Litronix duaJ 1/2" displays, Moatek 
50250 super clack chip, single I.C. segment driver, 
SCR digit drivers. Greatly simplified construction. 
More reliable and easier to build. Kit tindudes ail 
necessary parts [except case). P.C. Board and Xfmr 
optional. Elimiriate ihe h^sle — avoid the G314' Do not 
confuse with J^on-Alarm ^ils sold by our cojnpetitioTi' 



P.C.B. - S3.00; AC XFMR 



SI 50 $9.95 KIT 



MUSICAL HORN 

ONE TUNE S„-PLIED WITH EACH KIT. ADDI- 
TIONAL TUNES - S3-S5 EACH. SPECIAL TU\ES 
AVAILABLE - YOU SUPPLY THE SHEET MUSIC 
WE SUPPLY PROGRAMMED PROM TO YOU. 
STANDARD TUNES NOW AVAILABLE: 
-DIXIE -EVES OF TEXAS- ON WISCONSIN -YANKEE 
DOODLE DANDY -NOTRE DAME FIGHT SONG -PINK 
PANTHER - AGGtE ViAR SONG - ANCHORS AViAV - 
N6VER ON SUNDAY - BRIDGE OVER HIVE-R KWAI - 



JUMBO LED CLOCK KIT 



CAR & BO.AT KIT 

$34.95 



HOME KIT 

$26.90 



FEATURES: 

A. B5vjn:ar Jtjr:ibo .5 inch LtD array. 

B. MOSTEK - 50250 - Super Clock Chip .| 

C. On-board precision crystal timo base. ,.f)OD 

D. 12 or S** hour Real Time Format. ' 

E. Perfect for cars, boars, vans, etc. 

F. P.C. Board and all i:arts [less case] included. 

Alarm option — SI. 50 
AC XFMR SI .50 



,L'i;' 



$16.95 KIT 



RAMS 



CPUS 



21L02 - 50DNS E/11.50 

21LQ2- 250NS 8/15.95 

2114^ 4K M.S5 

1101 A- 256 8/4.00 

1)03- IK 39 



Z-80 includes manual 30.95 

Z— 80A include? manual . , - 44.95 

aoaoACPU s isr. . - 11.95 

8008 CPU S BIT .... - B.95 



PROMS 



1/02 A - IK ~ 1-5us 

2703 -SK Intel - 450iis . . 

5204 -4K 

E2S129 - IK 

2708S - 8K s:gne-■cs650^s . 



3.95 or 1 D/35.00 

14.95 

7.95 

2.50 

-.■-■ .... 9,35 



CESSOR CHIPS-MICROPROCESSOR CHIPS-MICROPROCESSOR XHIPS-MICRDPROCE 



8212 - I/O PORT. . - 3.50 

B214 - P.I.C - - 12.95 

8216 - NON iWERT BUS - 4,95 

8224 - CLOCK GEN 4.95 

8226 - li^VERT BUS - 3.95 

PIO for 2-80 - - . 1f-95 

CTC for Z-80 14-35 



822S SYS CON r ROLLER 8.20 

8251 PROG. CO'vlM. INTERFACE 10.95 

8255 PROG. PERP. INTERFACE 13.50 

8B20 DUAL LINE RECR 1.75 

3330 DUAL LINE DR 1.75 



2513 CHAR. GEN 7.50 

8S3B QUAD BUS. FIECR 2.00 

7<ILS13SN - 1 'S DECODER 99 

8T97 ■ HEXTRl STATE BUFFER 1.25 

1488/1489 ■ RS232 1.50 

TR16C2B UART 3.95 



NTER CHIPS-COUNTER CHIPS-COUNTER CHIPS- COUNTER CHIPS- COUNTER CHI 



IViK50397 6 digit olapsad timsr 8.95 

MK50250 Alarm Clock 4.99 



MK50380 Alarm chip 

IV1KB0396 - 6 digit up/down counter 



. . . 2.95 
. . 12,95 



MK5002 
IV1K5021 



4 digit counter S.95 

Cal. Chip w/sq. rt 2.50 



ITT DUAL SENSE AMPLIFIER. 
75234 AND 75235. 49c each 



SPRAGUE 
AMP. TD10 



DUAL DIFFEfiEMTIAL 
1 49c each 



GENERAL INSTRUfifiE 
1N82AG 



NT DIODE. 
19c each 



FLAT PACK 5400 SERIES. 
SPECIAL BUY FROM ITT. 
20 Assorted Devices for SI .00 



blSC CAP ASST. 
P.C. leads. At least 
10 differei; rvalues. 
Ipcludas .001, .01, 
.05. + other Stan- 
dard value;. 

60/$1. 



1000 MFD 
FILTER CAPS 
Rated 35 WVDC. 
Upright style with 
PC teads. Many 
popular values. 

4/$1,00 



39 MFD 
16V Mallory 
Electrolytic 

15/$1. 



THERMISTORS 

MEPCO - NEW! 

1.5K0HM 

5/$1.00 



7500 Mallory 
30WDVC 
Computer 
Grade Caps 
S3.00 each 



RESISTOR 
ASSORTMEiMT 
PC leads 
A gond mix 
of values. 
SPECIAL! 

200/$2. 



POWE R 

RESISTOR 

150HM 

25Wby 

CLAROSTAT 

75C ea. 



IC s from XEROX 

IC's Removeri frcm PC hoards. All tested; full spec. 



7400 - 9c 
7402 - 9c 
7404 - 9c 
7410- 9c 
7456 -13c 
7420 - 9c 
1402A -50c 

GKF.AT BUY!! 



7430- 9c 
7440 - 9c 
7437 -10c 
7433 -10c 
7451 - 9c 

7474 -16c 

7475 -24c 
LIMITED QUASriTY, 



7493 26c 
74121 22c 
74123 -32c 
74155 -22c 
74193 - 3ic 
S233 35c 
Intel 1302 
45c 



ITT Part # SAJ 101 ^^^psov^ 

IDEAL FOR ELECTRONIC '^ 

MUSIC CIRCUITS -7 STAGE Ar\^ 

FREQ. DIVIDERS. 45^0' 63. 



MICRO-DIP by EECO $1.95 

NEW SERIES 2300! 
WORLD'S SMALLEST BCD CODED DIP SWITCH! 
P.C. Mounli 2300-02G-1248; 2300-1 2G- 1 248 compliment 



JOY STICKS 
4-1D0K 
POTS 

$3.95 ea. 



P.C. LEAD 

DIODES 

1N4148/1N914 

100/$2. 



IC SOCKETS 

14 pin ■ 5,-Sl.OO 

15 pin - 5/31.25 
28 pin -S/Sl.OQ 



TRIM POTS 

1OK,20K. 

25K 

10/$1.00 



Slide £wiic1i A^s[. 
Our bsst sfjilej. In- 
C^u^i minialure & 



12/1.00 



1N4002 

lA 
100 PI V 

40/$1. 



CALL IN YOUR BANKAMER- 
ICARD (VISA) OR MASTER 
CHARGE ORDER IN ON OUR 
CONTINENTAL TOLL FREE 
WATTS LINE: 



Te.xas Residents Call Callectj 

214/271-0022 
1-800-527-3460 

DEALER INQUIRIES INVITED! 



Zerms ~ 60 'Day 
Money Mack Quarantee! 



NO COD'S. TEXAS RESIDEiMTS ADD 
5% SALES TAX. ADD 55; OF ORDER 
FOR POSTAGE & HANDLING . OR 
DERS UNDER S10. ADD 75c HAND 
LING. FOREIGN ORDERS - U. S. 
FUNDS ONLY! 



210 



Or6ers over $15. - Choose $1. FREE MERCHANDISE! 



S2 




for the famous 



HAMKEYS 




Model HK-1 



. i^c- v.r,r, HK-S ^r i^ry 

rfieci^'Omc K>3vf?r 
' li*?avy base '-vith non-sl;p 

; ubbcr 1v.a\ 
■ [-'adclles r-e\/e?[iib!o for wido- 



r oiose- 



'29 



95 




Te'm.rLil'^ ' ec or olsc-s S /5 esc 




Model HK>2 

■ : ■v-itf S5 HK-1 r-ss base '.o\ 
■ nc^Jrporanu^^ ,-n f>v^n keyer 

$4095 



i9 



Model HK-3 





Mfivy lyoe k-TT'b only $2 



• Sr'mie ^5 sbovf' 
u-., base 99.95 



^ Speed, volume lone and weighl 

controls all mounled on Iront 

panel 
■ For use with external paddle, such 

as HK-1 or HK-4 
' Can be used as Co'de practice 

oscillator Willi straightkey such as HK-3 



^--Vr^ooeMoci 512.00 



Model HK-5A 
Electronic Keyer 

• New Cabinet Colored-Keyed 
t<i Match most modern radio 
equipment 

• iambic Circuit for squeeze 
keying 

• Seif-^corrolehng iJo'ls and 
dashes 

■ Do! memory 

- BaEiery operaied wi:h 

arovjsicn lor exrerna^ power 
Built-in s3de-ione monitor 
Grid^lock or direct keying 



$ 



69 



95 



FOR NEWOR USED 
AMATEUR RADIO 

GEAR . . . we're specialists 
and carry in stock most of the 
famous-brand fines. Or, we will 
talk trade. 



FOR FAST, DOOR- 
STEP DELIVERY 

give us a call. You'll be amazed; 
for we guarantee we'll ship 
your equipment the same day. 
Plus, most shipments are PRE- 
PAID. 



TO SAVE MONEY 

. . . join thousands of our satis- 
fied customers who buy from 
us as easily as from their local 
supplier. So, remember your 
call is Toll Free. 



.'^.^1 



We welcome your Master Charge or Bank Americard i 

HAM RADIO CENTER, INCi 

8340-42 Olive Blvd. P.O. Box 28271 St. Louis, MO 63132 



H2 



211 





DIODES/ZENERS 


SOCKETS/BRIDGES 


TRANSISTORS, LEDS, etc. 




1N914 


lOOv 10mA -05 


8-pin pcb .25 ww .45 


2N2222 NPN (Plastic .10) .15 | 


1 N4005 


600v 


lA .08 


14-pin pcb .25 ww .40 


2N2907 PNP 


.15 


1N4007 


lOOOv 


1A .15 


16-pin pcb ,25 ww .40 


2M3906 PNP 


.10 


1N4148 


75v 10mA .05 


18-pfn pcb .25 ww .75 


2N3054 NPN 


.35 


1N753A 


6.2v 


z .25 


22-pin pcb .45 ww 1.25 


2N3055 NPN 15A 60v 


.50 


1N758A 


lOv 


z .25 


24-pin pcb .35 ww 1.10 


T1P125 PNP Darlington 


.35 


1N759A 


12v 


z .25 


28-pin pcb .35 ww 1.45 


LED Green, Red, Clear 


.15 


1 N4733 


5.1v 


z .25 


40-pln pcb .50 ww 1.25 


D.L.747 7 seg 5/8" high corn-anode 1 .95 | 


IN 5243 


13v 


z .25 


Molex pins .01 To-3 Sockets .45 


XAN72 7 seg coim-anode 


1.50 


1 N5244B 


14v 


z .25 




FND 359 Red 7 seg com-cathode 


1.25 


1N5245B 


15v 


z .25 


2 Amp Bridge 100-prv 1.20 
25 Amp Bridge 200-prv 1 .95 






CMOS 




- T T L - 




4000 


.15 


7400 


.15 


7473 .25 


74176 1.25 


74H72 .55 


74S133 


.45 


4001 


.20 


7401 


.15 


7474 .35 


74180 .85 


74H101 .75 


74S140 


.75 


4002 


.20 


7402 


.20 ' 7475 .35 


74181 2.25 


74H103 .75 


74S151 


.35 


4004 


3.95 


7403 


.20 


7476 .30 


74182 .95 


74H106 ,95 


74S153 


.35 


4006 


1.20 


7404 


.15 


7430 .55 


74190 1.75 




74S157 


.80 


4007 


.35 


7405 


.25 


7481 .75 


74191 1.35 


74 LOO .35 


74S158 


.35 


4008 


.95 


7406 


.35 


7483 .95 


74192 1.65 


74L02 .35 


74S194 


1.05 


4009 


.30 


7407 


.55 


7485 .95 


74193 .85 


74L03 .30 


74S257 58123) 


.25 


4010 


.45 


7408 


.25 


7486 .30 


74194 1.25 


74L04 .35 






4011 


.20 


7409 


.15 


7489 1.35 


74195 .95 


74L10 .35 


74LSO0 


,35 


4012 


.20 


7410 


.10 


7490 .55 


74196 1.25 


74L20 .35 


74LS01 


.35 


4013 


.40 


7411 


.25 


7491 .95 


74197 1.25 


74L30 .45 


74LS02 


.35 


4014 


1.10 


7412 


.30 


7492 .95 


74198 2.35 


74L47 1.95 


74LS04 


.35 


4015 


.95 


7413 


.45 


7493 .40 


74221 1.00 


74L51 .45 


74LS05 


.45 


4016 


.35 


7414 


1-10 


7494 1 .25 


74367 .85 


74L55 .65 


74LS08 


.35 


4017 


1.10 


7416 


.25 


7495 ,60 




74L72 .45 


74LS09 


.35 


4018 


1.10 


7417 


.40 


7496 .80 


751 08A .35 


74L73 .40 


74 LSI 


.35 


4019 


.60 


7420 


.15 


74100 1.85 


75110 .35 


74L74 .45 




74LS11 


.35 


4020 


.85 


7426 


.30 


74107 .35 


75491 .50 


74L75 .55 




74LS20 


.35 


4021 


1.35 


7427 


.45 


74121 .35 


75492 .50 


74L93 .55 


74LS21 


.25 


4022 


.95 


7430 


.15 


74122 .55 




74L123 .55 


74LS22 


.25 


4023 


.25 


7432 


.30 


74123 .55 


74H00 .25 




74LS32 


.40 


4024 


.75 


7437 


.35 


74125 .45 


74H01 .25 


74SO0 .55 


74LS37 


.35 


4025 


.35 


7438 


.35 


74126 .35 


74H04 .26 


74S02 .55 


74LS40 


.45 


4026 


1.95 


7440 


.25 ' 74132 1.35 


74H05 .25 


74S03 ,30 


74LS42 


1.10 


4027 


.50 


7441 


1.15 


74141 1.00 


74H08 .35 


74S04 .35 74LS51 


.50 


4028 


.95 


7442 


.45 


74150 .85 


74H10 .35 


74S05 .35 i 74LS74-, 


.65 


4030 


.35 


7443 


.85 


74151 .76 


74H11 .25 


74S08 .35 


74LS86 


.65 


4033 


1.50 


7444 


,45 


74153 .95 


74H15 .30 


74S10 .35 


74LS90 


.95 


4034 


2.45 


7445 


.65 


74154 1.05 


74H20 .30 


74S11 .35 


74LS93 


.■95 


4035 


1.25 


7446 


.95 


74158 .95 


74H21 .25 


74S20 , .35 


74 LSI 07 


.85 


4040 


1.35 


7447 


.95 74157 .65 


74H22 .40 


74S40 ".25 


74 LSI 23 


1.00 


4041 


.69 


7448 


.70 74161 .85 


74H30 .25 


74S50 .25 


74 LSI 51 


.95 


4042 


.95 


7450 


.25 


74163 .95 


74H40 .25 


74S51 .45 


74 LSI 53 


1.20 


4043 


.95 


7451 


.25 


74164 .60 


74H50 .25 


74564 .25 


74LS157 ■- 


.85 


4044 


.95 


7453 


.20 


74165 1.50 


74H51 .25 


74S74 .40 


74LS164 


1.90 


4046 


1.75 


7454 


.25 


74166 1.35 


74H52 .15 ' 74S112 ;90 


74LS367 


.85 


4049 


.70 


7460 


.40 


74175 .80 


74H53J .25 74S114 1.30 


74LS368 


.85 


4050 


.50 


7470 


.45 




74H55 .25 






4066 
4069 


.95 

.40 


7472 


.40 
















4071 


.35 




LINEARS, REGULATORS, etc. 




4081 


.70 




8266 .35 


LM320K5 (79051 1.65 LM340T24 ,95,. 


LM723 


.50 


4082 


.45 




iyiCT2 .95 


LM320K12 1.65 LIVI340K12 2.15 


LM725 


1.75 








8038 3.95 
LIVI201 .75 


1 MIOriTR 1 RR 1 ISfl'a.ink'lE 1 TC 


LM739 1.50 
LM741 18-14) .25 


9000 SERIES 


LIVIOZVJ 1 O 1 .DO 

LM320T12 1.65 


L'lVI340K18 1.25 


9301 


.85 


LM301 .25 


LM320T15 1.65 


LWI340K24 .95 


'" LM747 


1.10 


9309 


.35 


LM308 (Mini) .75 


LM339 .95 


LM373 2.95 


LM1307 


1.25 


9322 


.85 


LM309H .65 


7805 (340T5I .95 


LM330 .95 


LM1458 


.95 


95H03 


.55 


LM309K (340K-51 .85 


LM340T12 1.00 


LM709 (3,14 PIN) .25 


LM3900 


.50 


9601 


.75 


LM310 1.15 


LM340T16 1.00 


LM711 .45 


LM 75451 


.65 


9602 


.50 


LM311D(Mini) .75 
LM318 (Minii .65 


LM340T18 1.00 




NE55S 
NE556 


.50 
.95 


MEMORY CLOCKS 




NE565 


.95 


745188(8223) 3.00 
1702A 6.95 
MM5314 3.00 
MIV15316 3.50 


INTEGRATED CIRCUITS UNLIMITED 


NE566 
NE567 


1.75 
1.35 






19 


2102-1 


1.75 


7889 Clairemont Mesa Boulevard, San Diego, California 92111 




2102L1 1.95 
TR 1602B/ 


(714) 278-4394 (Calif. Res.) DISc'oiNVs 


1 1 i 1 \J^J^^lmJf 

TMS6011 6.95 


All orders shipped prepaid No minimum Total Order 


Deduct 

r-rr/ 


8080AD 

8T13 

8T23 


15.00 
1.50 
1.50 


Open accounts invited COD orders accepted $ioo-S300 10% 
Discounts available at OEM Quantities California Residents add 6% Sales Tax $301 -$1000 15% 


BT24 


2^00 


All IC's Prime/Guaranteed. All orders shipped same day received. 3ilUUU - Up 


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2107B-4 


4.95 


24 Hour Toll Free Phone 1-800-B54-2211 MasterCharge/BankAmericard/AE 





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EE? 



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* 1000 ohms per volt 




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POLY PAKS 

p^sJo^ri SUPERMARKCT 

— FJOV 719 7^73MAGAZIN^PECLA^^ 



burnt 
0-15 



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p.l 



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AC 



ft.lOflO: 
n-irj-ir^r-l'^no: DC cuneni 

SensiT i:[v lOOO ohms/v. I: 
AC-DC. 1" ■ -i T^eniile t-"., 



ant 



:.Ik 



. '/''- 




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$5.50 TV GAME 
JOYSTICK 



f<^ 



A HI 
Fl 
fncludes four laOK pots 

For TV & cnmp-ji<;r eanipr., 
iir.rl. quailriijiliouic btilanc- 
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Cat. No IIAIBOB 



^POLY PAKS "CHIPS" 
jfc AWAY IC PRICES! 

^^ Order Cat. No, i lAflO-TH and Typo No. 

Type Sale 

l: JCM7305 Stouwaieh Si4_9& 

Ll AV3-a500-l SJ* TV Games . 9.95 

._i MM5330 iji/j Disit dVm - - . 4.95 

! J e03flC Voll Control Otc ■+.95 

[ ; KR237S tncudor ROM BCD . . , . G.95 

J 9SH90DC 3S0 MKz PrprcPlcr . . . a. SB 

MC14-11D Touch Tone EJicndcr . g.95 

MK2O02P CTiar. Can. (2513 equal J 3.^5 



IT OPEN FACE DPM 

• Dual Range! digIT.AL PANtL METLR 

0-2V, 0-200mV 



I'KICI'T .■■kNyiV'JJl'lKK . 



.-.ii.Ei- .-iSU^^E.-. 



$22 



r .. M TOUCH-TONE 
^l^'^ij ENCODER KIT 

i]l romp-..- Q 11^3362 Touch Tone- IC MCl-l-aiOP 

with M [i 11A3J49 12-Key -lohthHr touch Ktyt-o. 

I^ cry>l"L LI 11A363S 1,00 nrtH^ Crystal , 

0.11A3385 □ 11A33S3 AutoPiitch PC Boarrf 



ECC INDUSTRIAL 

SPEED 

CONTROL 
$g95 



3 FOR 
$16. [ 




r 11^ VAC T.^11- 





S-Tiark 

TAPE 
TRANSPORT 



EitcnUi^nL 



Unns, Sii'.r* D X ti x ;!; ." 
Wt. I |h:,.Cal. No,JlA^6lO 



_; 72D7A/7206^■r■ 

n ICM7107 S'/j Oi^it DPM 

r'^A-M^Sie A|«f-tD Clock - 

aa&0& Micj-oprac«^&or 

'■ I702J Erasable PROM 

270& SK EPROM . . 

.. 2102-3 IK RAAf ... . 

r DIP R^e- sJ.ea h 
Switches v^urct^o^ 

Cit. No. Sivltchs 

rn itA3669 3 ^^ 

LI llA3t>21 4 ;> 

ri iifl3S7"0 s ^: 

O 11A3671 G ^ 



, PJilr 



$1.00 




$250 



SPECTROL His :: n ;; 
SKINNY-TRIMS" [" 



^najftfid 2s Ti 
JlIA^aee Single 




C 3 AMPS 

516.88 

□ 4 AMPS 

$19.95 



(Hl/t-IT .SV'JtL-lp. 1^ 

, hiiilt-L:i rjr<;iii[ l.--', 
Lin vac: «I< Hr, N 
;, Cat. No.llA3a52 



CotrtpIeteTy 
wired 



12 VDC f(^ 3 Amps output 
Regulated, continuous duty 



BARREL KIT ^ZD^ 

CALCULATOH 

KEYBOARDS 

10 for $1,9 

liciii kayUoard" al rii 
Cai.Hc. 11A1524 





BARREL KIT;3±5 /^ 

SOUND rRlGGERS|_.!y 

3 for -^^-^rt^^^- 
$Ip98 C;^^ ■■ ■ 

'■HmthI flap" seitl'.ilitci.tr.v*. 
.ttii miii^ HinnliJicr, triggers 
SOl^. Uac ior jJfirma. etc! 

_wt. i: C7rs. No. itAaeas 



BARREL HIT ;fia4 
l.:i-WATT METAL FILM 

150 for vi^?^ 
$1-98 ^**^ 

ino::- meUI :^lm rcsLS- 
Jor.^. Lor.g :6m1s. Il.fi3413 



'barrel KTT tZ-53 
,L(HE CORDSrE:^^ 

Sfor .J. 

si.ee ". "-' 




A 530 Kfin. Hated at 1200 watte, A (wrjr flJiiorJito 
eli-ouit tat eoatxtiWJjiB maay elfictricnl aad electronic 
■1«t1c«ii, EitGil7 controlii s^ede of r[actriQ driUe, brueh 
i-TPC niotora, eu:. Built wlih. k^arr duvy MJiimLan::! IrAm- 
IaC. ComptALe vUh extcniai pot, ti^r vaiiablo 

apesd contTO-, Hekvy {^uty colorvil 

wiiva (or IISVaC CO oSie^i, aui item «0 t* caaifOlt*d, 
10/32 TP.iiiniiiT^ Dl'jd. OcttPe-rJoriDB aar prarXoiiB !i*lL, 
mil. Wiih hwlccp dinpKb. Vs<e ui triHp*rs.tQTt con- 
IrolloT tflo. Wt. 3 Ibi. Cat, N«. 11A33»^ 




'. 1 IA4011 i 



$5.95 
5 GIGAHERTZ 



MlCROWAVfi POWER TRANSISTOR 

■-. n I I E \ f t e M N 

1 1 T I Ti 1 H ,1. I ^ f^ I- I ICh rri r 



gg^Great for Light Shows, Strobes. 
Light Displays, 

Slide Projector! 

• Worth mony 
times our 
asking pric«. 

• Wide angle 
focusing lens! 

5 IN 1 PROJECT-ALL jncn 

SHOE PROJECTORS IZ^" 




;;,VV ■.'..\J YCilRS!!.! 



EXCLUSI^^^/ 



GUARANTEED 
60% YIELD ON 
UNTESTED 



I BARREL KIT ^264 
PHE-CUT-N'TINN 
HOOKUP WIRE 

200 leneths*$1.98 



JBARREL KITJ/zdb W/AfBAHBEL KITfH4 

DiaiT READOUT/y^i'HOBBV oiMi»~i-'!i>f, ■, 
^MOOULES "J 

., 5 for $1,987, 



■::! bai 



. c^r- 



BARREL KtT :Z2 1^ 

IC SOCKETS ^''# ij 

8 for It'-"' 
$1.98 

ioiir 1 3-pin. 



BARREL KIT :;1G2 
JUMBO RED LEDS 

15 for $1.98 




rn txz^li.. iVt. 



IJ-OJA i\ WS 
ROMS i=t4>i 

3for$1.9l* 



ARREL KIT :;20';/ "■ 
MPNI BLOCK / 

jCAPAClTORS i-"'- 

SO for $1.98/ 



rjn fcijbmini 

:ij>p:ir.Ti.kt>J!s, 

llAftSZS 



p>-| ARREL KIT r2 0i 

cv indicato'rs 

W/le3(*5 

15 for $1.98 

ilismpB llU'ontory: Wfirtli 
Cat. Ho. 11A352S holj>jy 



BARREL KIT ^1 tiS^^:^ 
MINI THUM POTS/^^J 

30 for io= fO 

$1.98 y-'ji' 

- 1. v.".l,ies :!00 tn 1 Tiii,^ 

f..iF ,-. hL,V. .^irisli [-i-'n. 

, ^\. V.^. fi OE, 11AJ345 



70 



zy.'^Ei 






'^' 



ft, jni)ru'»" . 



2 ozs. *2<10 
o. llA3gS9 



BARREL KIT ^239 

SHIELDED CABLE 

40 -ft. $1 .98 

Vl.J ^iv1!5. ^VLT-jOi; l-tOftd. 

pljj J-: -Vl'J, 2 2 ep. vinj.-; 
"a^ket. '.Vt 1 lb. 
Caf. No. I iJt3s77 



BARREL KIT 

Xt> AMP IHLrNE 
BRIDGES 

20 for ¥1,98 

Pactoij' dumpoil in 
^^'e can't loat "em, 
the |,ri,-c ,ou c. 



,ft't 



BARREL KIT :iea . 
HOBBY VOLTAGE/ Jl 
REOUUITORS '■'-^'- 

10 for ¥1.98 



BARREL KIT ^13fi 
PANEL SWITCHES 

A-" 130 for jjy3 



BARREL KIT^12S 
MENI-DJP JC'S ^ 



100 forSl.gS 



l.lA3ZSa 



ARREL KIT =193 
NYLON GEARS 

40 for ^S 

$1.98 ^iKiffisC 

Widft vnrlfjiy of aizQi! I' 
3" irniirn Inr \.hs nice! 
ical ctiu" t!'a.m hobby i 
Wl. 10 or:., Ho. 11A3^ 



1 I A3 245 



BRIDGES' KIT^2T0 
20 for. .i, -:^ 

$1.98 ^^ 



BARREL KIT tfZ3C 
HALF mCM 

READOUTS 

15 for$1.9Sj 

HOBBY - ^ 

■From lactc.'y ti 

rludts FaiKhjiril IvNT)-5aD 

S; E07';t. 1143S23 



BARREL KIT : 
40 PARTS 

S1.98-— -- 



illlc. h;L,i'r''li 

Cat. N. 



. TT hriTLfd.^. riirr 



facloi 

.'1-1. -il. Wt. 12 
IIA3401 



BAHSEL KITpi27 
AXrAL ELECTROS 

40 for 
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BARREL HIT ^12fi 
UPRIGHT ELECTROS 

40 for -fl g^ij 
$1.98 -V^S 

Ijnf !'• r^OOmr lit [r.i:;n:r 
of vvUiises. ' 10 '^ nim-ko 
■r c^ad. 11A322G 



BARREL KIT f lis 

MOLEX i„„,:..;jj 

SOCKETS g„„c lA 

150 for c...no,l 
S1.9S iiMi'w 



BARREL KtT ;ID9 A 

Itermihal strips^ 
'100 for $1.98 1 



p-ii 



.Liit^E^r 



.aJii^r !luj 



[^V-. 



L KIT rETjS^^jl 
BONAHZA]fiB' 

11- $1.98 ^W, 



BARREL 
HAT. IC 

100 for 1 

T7.1XI >'. in barrels r.ir.t.i^s, 
7 iJt] .1, ROMS, DTL S. rer- 

chipp -MiJ :aor<f, Wt, 12 or.s. 
Cbl. No. 11A2S60 



BARREL KIT H^i^ 
HDBBY NPPl POWER 
TRANSISTORS 
15 for $1.98 

TO-3 ;:c-.vcr^ 




hi-lrl.. 



^-1:1. Cat. Ho. 1 ;A2S17 



BARREL HIT 

PRECISION 

RESISTORS 

200 for 
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MurS'i-J and vn 
'A, S wfttis.No 



I BARREL KlT^SG 
■lOBBY LE1>S 
^0 for S1.9S 

WOVv: Top V.S.A. 
<luT,ins dLscfclL^i in I 



Wl. 4 r.K!i. Cat. K* nA2SS5\Vi. 



.Strip rttaf-ura.-i.Lrf.rs 
il-jmp i- yr.Lir f;,::n. ] 
Ib.Cat-H'o 1 lA3l^g < 



BARREL KIT ;I104 
SLIDE VOLUME^ 
CONTROLS 

lO for m 
$1.98 S 

Cm-No, liAJ057 



^^ 



S ARREL KIT ^101 
RESISTOR SPECIAL 

200 for _,^-^S^. 
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rn,rlud.T.: !,^. ^A. 1^. 1. ^, 



BARREL KIT tsa ^-^ 
PHOTO ELECTRIC MS* 
CELLS 77* 

lO for $1.98 ^ 

Ask'„, GE iyj>i!5, CDS typpp. 
ll:>:.cd hy (atiiriri-. njc jnh 
for us [.r r^f'jftraie. iilOTi 
^'ood_ Cat.Ffo ItAlOSZ 



BARREL KIT =83 
LM-340T VOLTAGE 

REGULATORS 

15 for 51.98y?, 



,_ -, BARREL KIT :^T1 g* 

^^J^^CAPACITOR SPEClAll 

^jy^lOO pcs^f^tjm^ I 



til. 



BARREL KTT ^31 
METALLIC infiTlV 

RESISTORS -V^y 

100 for $1.98 



-.ol. 



HA T^Qg 



BARREL KIT ?30 

PREFORMED 

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200 for $1.98 



Mo-llA360SiC(I 1- iCJod 



XiA;24 2B 



BARREL KIT C7 . ^^ 
VOLUME %!d^- 

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30 for y^^ 

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KillEli^.. tiuzii^. vnfk-IV of 
..irriji!] ijinJn. Can. 1 tA S42-] 



BARREL KIT - 3 ,-<7j-- 
lH4l44/fil'l -'t';**^ 
SWiTCHLKG DIODES 

100 for $1.98 

Cat.No. JIA2418 Untested. 



t;<{0Qi1 Cat.No 11A173S 



BARREL KIT i^'zT 
PREFORMED DISCS 

150 for '<^-^; 
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K1T^1^§^ 

DIP rc-51^ 
il.98 '^^ 



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75 for S1.98 

Mflrk-cd 11 ^^ntl IC pin dips, 
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2 WATTE HS 

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:63 



BARREL KIT 
POLY5TVHEHE CAPS, 

100 for 
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HALF WATTERS 



fyil u..i hy 
col or- coded 



rviLilcn^ in 



lIAi04G T:: 



L fiLCly 



a|^>| 



ipJ.Cat.No.llAaTZa 



BARREL KIT /^2G BARREL KIT ;^20 

PLASTIC TRANSISTORS LONG LEAD DISCS 

y*P„*2'^ v-^J fc 1 100 for— fC^ 
$1.98 '^— ■■ (c-i QO 7 f^^ 

urers. Wt. ■? i..=s.J,lAz«j4 JCat, llflisaa lOO ff s-m 



:^ 



BARREL KIT .-S. f^dft 
SLIDE SWITCHES Y-=l 

30 for $1.98 

d.!i.:v •A.'yy r,-il: lor IflOt i.>! 
Cat.Np,HA?7SelOO fwff'Jwl 



BARREL HITn^^ZS/ 
DIPPED MVLARSL* 

60 for $1.98^ 

■^r.L.-.j- rir:-}^ l-(ji;:i.-ii> fai-:-i- 

v; r*: ";r';'l£ <■«'■ ir. "tai-re'v. 

Cat. No 1142597100^ gOJUtl 



TeriiTs: Add pcstacp Rated: nei 30 
Phone : Wakftf.e:fl. Mass. (6IT) 24a-3S29 
Retail: 16-lS De] Cur^r.ine St., Wak^^ii&ld. 

POLY PAKS 

P.O. BOX 942A l-YNWFIELP, MA. 0t940 




ilPoly Paks I nciV Wakefield, Mas^,. U.5.A. 1377 



MINIMUM ORDER — S6.00 



213 



Armchair Copy 

with new $67 

RRK7 

Actiue Antenna 

Shortwave Listening 

Our ONLY occupation is 
supplying everything you 
need to tune the mediumwave 
and shortwave bands — and 
identify what you hear. Our 
NEW mini-catalog details 
Barlow Wadley, Drake and 
Yaesu receivers, WORLD 
RADIO TV HANDBOOK, logs, 
receiving antennas & tuners, 
calibrators, FM or TV guides, 
AM pattern maps, QSL 
albums, ITU publications, 
RTTY displays, CONFIDEN- 
TIAL FREQUENCY LIST, 
clocks and alS SWL books. 

GILFER ASSOCIATES, tNC 

P.O. 80x239, Park Ridge, NJ 07656 

l.iJiU.ii,.l^l.,lJiii„UiJuL.t^iJiiiaL.ij^l.Uild G6 






2 METER 
CRYSTALS 

MANY 
IN STOCK 

FOR THESE RADIOS ON 

STANDARD ARRL REPEATER 

FREQUENCIES 



Clegg HT-146 

Drake TR-23 

Drake TR-33 (rec only! 

Drake TR 72 

Genaue 

Heathkit HW-2021 

(rec on!v) 

Heathkit HW-202 

toom/VHF Eng 

Ken /Wilson 

LafayeUeHA-146 

Midland 13-505 

Regencv HR-2 



Regancv HR-212 
Regency HR-2E 
Regency HR-312 
Regencv HR-2MS 
S.E.E. 

Sonar 1802-3-4,3001 
Standard 1 46/826 
Standard Horizon 
Swan FM 2X 
Tempo FMH 
Trio/KenvjDod 
Trio/KsnvjDOd TR220Q 
Trio/Kenwood TR7200 



$3.95 EACH - IN QUANTITIES 
OF 10 OR MORE, S3.50 EACH 



Certified check or money ordei only 
NO CODs 



ROI-liV DISTRIBUTORS 
P.O. Box 436 

Dunelle NJ 08812 



B15 



PROUD OF YOUR CALL? . 
WORRIED ABOUT THEFT? 

Identify your FM transceiver with 
automatic code on each trans- 
mission. 




SMALL: 2' 
Installation: 



X 2 5/8"x 5/16" 
Only THREE wires 



WARRANTY 

Returnable for full refund within 
ten day trial period. One year for 
repair or replacement. 



PRiCE $39.95 



Ppd + S2.^0 
C:A. S.ALES TAX 



Your call sign programmed at 
factory, please be sure to state 
call sign when ordering. 



I 



AUTOCODE 

8116 Glider Ave, Dept S 
'Los Angeles, Ca. 9004S 

(213)645-1892 A36 




..<! V 



o^ .,exc^^ 



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214 




ECM-SB MK-II fm modulation meter 

■ O-SKHz peak reading linear scale, meets 
commercial standards 

■ Operates 25MHz to 500MHz 

■ Crystal contloUed {or easy operation 

■ Audio/scope output with, earphone 

■ Options: NICAD power PAK $34.95 

Charger $29.95 

Write or call for complete information. 
Send check or money order for $145 
plus $1,75 for 'shipping. Indiana resi- 
dents add 4% sales tax. Crystals for 
146.94MHz: $4.95. All other freq: 
$7.95. 

JECM Corporation 
1412 N. Weinbach Ave. 
lEvansville IN 47711 
812-476-2121 El 



ECM 



NEW! 
A $14.95 

Meter Calibrator! 



A quality volt-ohm calibrator at a break- 
through pricel Why put off calibration of 
your VOM, VTVM, or digital multimeter? 

Here's what you get: 

• Check DC volts at 0.100 V, 1.000 V, 
and 10,000 V 

• Up to 0.02% accuracy on volts 

• Check ohms at 100S2, Ik, 10k, 100k, 
and 1 meg. 

• Up to 0.1% accuracy on ohms 
Battery powered, uses 2-9 V batteries 
(not included) 

Uses hybrid IC precision reference 

Only S34.95 each. Please add $1.50 
postage. CA residents add $2.10 tax. 



Gary McClellan and Co. 

G10 



Box 2085 




1001 W. Imperial Hwy. 
La HabraCA 90631 



INSTRUCTOGRAPH 
MORSE CODE 



Since 1924 Instructograph has serviced the 
world with the most complete equipment ever 
devised for learning Continental code. You 
have complete control of sending & receiving 
AT ANY SPEED YOU DESIRE while ma- 
chine is running, without changing tapes (not 
cassettes). A complete course for beginners 
Incl. machine, 10 double sided tapes, key, 
manual, built-in speaker. Nothing else to buy. 
$98-50 plus UPS 121b. del. chg. Add 6% S.T. 
for Calif, del. For catalog on 45 advanced 
tapes write: Instructograph Co. Box 5032 
Dept. 3, Glendale, CA91201. (213)246-3902 



or 245-2250. 



117 



MORSE CODE 
INSTRUCTOGRAPH 



$5.50 VALUE 







\i you are like the rest o1^ us 
you've been readfrig about micro- 
computers . . . you're excited 
about them . . . but there is so 
much to understand and it all 
seems so complicated that there is 
no way to understand it. 

Hogwash. 

A n.ew magazine is being pub- 
lished "for computer hobbyists . . . 
for people who are beginners . . . 
neophytes . . . novjces . . . people 
who have no idea what a vectored 
interrupt is, but just the same 
want to learn about computers 
ar>d have fun. 

A home computer system can 
cost you a bundle if you don't 
know what you are doing. Kilo- 
baud could save you a lot of 
money . . . others have learned 
the hard way- Kilobaud is a sort 




of giant club newsletter for com- 
puter hobbyists, a place to tell 
each other about the problems 
they've had — and the solutions. 
It's a magazine filled with great 
articles ... all written so you'U be 
able to understand them. 

You want to know about 
hardware? Read about the new 
MITS Z^SO CPU in Kilobaud, 
simply explained by the chap who 
designed the circuit. Or how 
about the best-selling TDL Z-SQ 
CPU . . . the designer has written 
about it in Kilobaud too. You're 
wortderjng about what cassette 
system to use? You can go crazy 
on this one . . . but before flip- 
ping out^ read the Hal Wal ker 
article in Kilobaud and find out 
what the problems are . . . and the 
solutions. 



MAKE MONEY 

Perhaps you've been thinking 
of the computer bobby as a way 
to get into a small business. Why 
not? This is going to be an enor- 
mous field In a couple of years 
and you can bet that those on the 
ground floor wiU have the best 
chance at the gold ring. Kilobaud 
will help you learn how to get 
Into manufacturing ... to become 
a dealer , . . a manufacturer's 
representative ... a service bureau 
... a writer. Never before has 
there been an opportunity like 
this. Grab hold and start getting 
your feet wet. 

KILOBAUD IS BRAND NEW 

The first issue was January 
1977 . . . and the magazine is the 
fastest growing and best accepted 
magazine in the hobby connputer 
field already. You doufat that? 
Just stop in at any hobby com" 
puter store and ask anyone you 
see. Kilobaud is outselling all 
other maga^iines combined . . . 
which says something considering 
the cover price of $2. It's fulJ of 
good articles and has a sense of 
humor. There are more articles in 
Kilobaud than you can read in a 
day . . . most readers comment 
that Kilobaud [ust has fo be read 
from cover to cover and this takes 
several days. 
I — — — — — — — 

I □ YES! Stan my one year KILOBA UD 
issue. *And send my FREE Tee shirt. 
1 SU MU lU XLU 



DO YOU WANT TO LEARN 
COMPUTERS? 

Some magazines emphasize 
OEM sysitems . . . some are vt/rit- 
ten more for computer scientists 
. . . Kilobaud is written for and by 
its readers . . . the hobbyists. 
You'll find great articles in there 
by well known hobbyists such as 
"Don Lancaster . . , Don Alexander 
. . . Pete Stark . . . Dennis Brown 
... Hal Walker ... Art Childs . . . 
Sheila Ciark . . . ajid many more. 
The emphasis is fun. "^ 

TRY A SUBSCRIPTION 

The cover price is $2 (tfiafs 
$24 a year), but the subscription 

""T-ate is only $1 5 for the year . , . a 
saving of $9,00, plus you get a 
Computermaniac tee shirt . . . 
hurry, limited number available. 
You can pay for it ^wlth your 
credit card {BankAmericard, 

"Master Charge, American Express) 
or you can even be billed directly. 
Send in the below coupon ... or 
call TOLL FREE 800-258-5473 
{during office hours). Please have 
your credit card handy. 

Your subscription will start 
with the^ next published issue, so 
al low about six weeks for any 
apparent action. If you would like 
to be filled in v^/ith the back issues 
they are $3 eafch and at last count 
some were still available. 



subscription for $15 with t/ye next pubfished 
:. Sizes for A DUL T$ ONL Y. 



-Calk 



Address. 
City- - 



_ State _ 



_Zip_ 



$15.00 enclosed. D Cash D Check D Money Order 

Bill: D Master Charge D SankAmericard D American Express 



Card # Inierbank # ^^ 

Signature Exp. date 

n Bill me direct. (I've signed above) 

*Tee Shirt sent when bill is paid. Allow six weeks for processing. 

Toll Free Subscription Number (8001 258-5473 
US only - offer expires 12/31/77 

pCTERbOROUqh Ntl074V8 73/11/77 



215 



WHAT HAVE YOU MISSED ? 



JUNE &3. & II .':; ;?i_.e DWQ I- S^JiCCf ~y- :>r 
*30. li-itfcasir's "^'PC^ i-.a-Vsi:&"-.iiT «f.*i-i.-i-¥ 
^t &7A o-.Mi ii.r^n.v !»n'>»'-i.tan, EC 3^8 a^iiL 

IX, haginn.-K"!; i'k using dC -4-53, rcr.yr Froior 
mnmg, -raiiaisTor cw TnonnBr, ac-442 ,im re:fly 
L:cinvBr5ion, mobile loactiilg coil5^ i nr.rc.isin^ 
rwo-eir seltN:tiuiiv TV \\\\.\\ ihe ART 26 tx, 
Tfi^-B vx Oil :?:=0. ARC 5 li^ T> 5^ i^. ARC 3 ty 
on 2M, 

AUG 63. Bailwv jp SV si i. iilcde i-uii-? gen^ 

|.J^ mad^, iiVi nresKln, V^E iJOsr-i iji^iigr. c::ax 
«H»<?i Ri^ ivftiiTerar. TX Tub* ;>.i 'In di=:isf 
P\W KjpiJlv. "LjrchEOK" Miu^o-.^h. 3t/»n o.piar- 
aTion, verrkal am \pfa, intra en iV^ii^r'^ .^ni. 

OCT 63. WBFM iJ-ansi:fin/Bi Ideas, 111^ [irOfJaga- 
titin. chen|> fans piJich. rBiTiclfl-iuned Yagi. 
coilsrruction hiins, nni roiipler. SS Vedical, 
filfliwcnt xfcrmfiT £:cnstiiic]ion. 7fL* nuviSTOi 
20"v€rl«i. !.al«ve]i€ Hi;" :i5 Tiods, fJuysT ■i 
Gwir.-« 4c; R:i ffir Tx, uriKJucl: aenSiUBi. rit>ver 
t\tC VFO •uiiio asTrDni>niv, piai^a^tftrio: 'i'" 

llQl--vie.--.e-. -ii— 'tHIcT F^! -(IE BT-'t 

Ff;B 6fl. ,?^? nij'ik;n3nrn!l gtxcj^tr, f>. d=sLi=n 
i09i3Si, rpajic lir switch, oiinifi^sker i^Ri-Nr !jf &^, 
40JV1 3W tx, lool-; ^T fiiSI ccuiprntTit, ladio 
grounds, 'lOM ?L Spticnl oril, iiBuirah^jt ion. 

MAY 67. QiJ^tJ Is^ue: 43;? Qunri q^ud (luad. 
■p,K.p.Tiided HF itij.id, Tv^o <?l quad, (Tiii'i iqLrad. 
■flOM (j^iStl. iiJ-irii^i expe' i-iTi^jr.ts. hsIJ ijno-rl. Th^ee 
et qjdad. 2■0^* (i)j,a<3, TilTCi-er 'jiiad, eA.iy i-o pr^irr 
quad. Qt,a;J p^ll^i!3CTap^.^, rET irl'n, lulic 
i':lQl:lcsKQD':itip H-- t.i:irni"iv IsaiS, jr:ft3" 
■st*'"ir nij "tIS ■ HF S£-9('c\v px geor-iii'ir <: cir 
;ji: liss-^p, C*;3 SOI -^riiiiSncKe FE" 'nv^-tf 

JUH.V 67. VE ham ladici, VEO hom^, dsh 
^dafiior. homB Ijrow tOiW^r, ironsiitoi ftcsign, 
'39 WoflQ's F^^iJr. fjnri plai-nj ant. GdZU beam, 
SSTV '^oniii!.r. UHF FET pi-earrsi-vi, |C "H" 

i-'OSSlWwi. h. ithicwil nai'- i.iuu. Hr^ir. HP ia 
-1X1 1^ 

OCT 67, HF po PC «j:* 'S. r^^<1 raTnio'. 
dtjiyrirs ilLg tjni;!",- coil*, FET rr^nurdrtcf. 
■S^T V [Jix Efisn. VH F ; nq pericflica. Fa;a;3lJlc 

di&oic, gai-TtrtuT 'Tiatch ■'.ujfj , old-ti^'T'ii'' dx ing, 
modarn dxiny. 

JUNE 68. Si.j!+.Ili5 liiiJti 1 rai.s-fOfj-iitr uicJ^i, 

B&S2Q5 '*■. AFS13 ATV ;:.. loi^ voJiwj? cic 

- »:jpplV. 3.^>p1li5 itoi^es PM fig cDmiTiWiJ-i^J xral 

TS^I rx rriortr. THA 1 3 Br> -532. 'laq rai/m^' 

Tjp« jSiTthf rlprj. 3Jf FFii* CC'^'-'^^a'" Bit>IIO 
qr«i:hv, RT 203 y-ijI^ib sn i^V. ARC 1 au^-d :x. 
RTl V rx TLP. 

JULY 68. Woatlun TOwcr ijons-ruction, tikaver 
towers, ertjctinif a telephone fofe. IC AF o^t:, 
"dB" dxplsiriCtf, ham ckib lips iPart 1 1 . 

SP-PT ^. ^rtor*3le wli^ ^32 FET r.Mcimps, 
ncnv^fiing TV i une*?. k:*1 osc JTiili.iilv, pb!^- 

i^'ten; IzQireciicrtS JJifi filJl. 5M fi,«'.^eii-5j 
IccrrcETicria Jijrt E9;. 2f/' rj^j ^mi: ^ h— i ;Il-!j 

T.-DS [Par-. 3:. 

NOV 66, i'^tl >:lgl f:IIf?.^S. solid St^li UQLJOle 

slioaiing, iC tfcq counn-f [mtny i;i.ors & 
o missions), '\\V' ii-.incliormers, sn^icc ccunrjf 
odVMev, P'lK.-ir jnfa, thm-wfre gnrs, 40M tran 

■siSTOf cw i'./rx. BC Sasrvi double (Hi\;vi\f?.ion. 
niuliifunctTCiri n:st«r, ropppr vjire si5i-r-5, Thi?i- 

hJrtK club. lips '-Pari S^ 

JAr; 69. S''Piif^-sscr ^o-vur^ssai . MA 12 ui- 
■. SC. sesn -i.-i-'^.^. iC i.'iJlag.^ ^C>cta\, 2F-" 
'.rails sto- ■:.(. L^ patj^r i^^ojt^P' l^ecir jFT 
Aiialysli'; iFifo, Ci\1 trarsj^tor r«. &ri3*'i -tq cc(i 
sn-le, RTTV ;ii.:tost5r'i. i-flK^fJ^^jng os(" sliLiilTlV, 
\a pwT 40 ckjv tK, sequifit-icil relay ■5-wi tithing, 
sifihtlHss opc-r.-iior'; briclHC, h.im c^lub ilps (P?ivt 
71. 

FEB 69. SiiT\' -3f-crj i-*ot) iot *j!;i s:;?ii. 

ifjnsistcr irtfo "iihclii T- :' -. ■;icvc'-j< r v. r^caie 
irt(<B*)stiiOn ^^nTt, sAtis i^r- ;e^ s-": ^I ■-. t ;Fb^i 
II 

MAR 69. Si.rialv.; imiv,* ~^ rjn I'mrla cbsap 

k<-i\f.(. betiisr l;^^!ancod irof.!uloroy , iransiSlOi 
uunlJators, Lining i:^lo^vcl:■. haL+iivove icedline 
ip\1o, Suriihi-- Conversiun BihiiogrLn-iliv, extva 
liten-se siudv (fafl ?l. 

APR 69. 2 LJ^'^i>irie> n^ope a<-:iO. m rfesFT'ii. 
Tw-a <rf PTT. vji.,nblie DC i-'M-d. S^-^R L!'.^'Hf& 100 
h I lj Tiafxei i^rie, some EiAn^i;^^ sfwr-^. EE 5"I0 
rri>rL';crK:of-i? maoi. rortJ me -Sr.' ^% ■." :•■., '^W 
lar.'der&r. eK:ia l.-ar«e s.iijJv IFair ^! 

MAY 69. 2M r.irnstire, 2lVt 3lw[, ry. .ifrnjator. 
QwrfC-Bcar "filtpi. s'lort VES, quad itjiiing. using 
iirMennaacopdj rne-isunnq am gain, phane patdi 
r-egs, SWR intiii::fn:or, 1S0M shorT verticals. 15M 
mi-itpnnB. HF ptopat^tiOO ijngles, FSK exciter. 
i^W sMmrity laad. i>i powflr linear, e^irj li.r:cn£c- 
^■y-Mi\ (rtg--- -i.'. Jl^^be'irJ liit(,-in efrav 

JUNE S9. Mi^rti n^va- pi-iP ^niif 3 fiC^. c ''■'' S'S^J 
:x, -*."^ er -i,-.'r,y:. 611 .-!jjnvflvifi'. 3M 5''B ■.■^»:^ 
/^.■''^^p UHr iv ell-wts. Al^ wiDSo mpjJL-.na-.a'. 
Lh-F F^- PMtJ»-lpS. HTTV r'-'i3-\i:Z'-^K.^ti,Hy.ir^ 

fifTri^riSig slijfl V Tp-S' f Si -11.. Mirtg .j.T' iiav: lies 
m,rii-VEE TO! 10-20M. 'J^! vio 



JULY 6&. AM rnoriulaigi. yr^TV 5ig yuii. GM kw 
linftgr, 43^ KW ."imp, 433 cj" ^x/E^^. GM IC 
cpnvga-T&-. ri««lio canTra'IrtcJ motfel5 RTTV ^C 



The back issues of 73 are a gold mine of intei'esting 
articles . . . just take a look at what's been covered . , . 
every possible interest. This is the most important 
library you can have for hamming. 

The supply of these back issues is very limited . . . and 
when these are gone, that will be it. Don't miss out by 
procrastinating. Treat yourself (or a ham friend) to a 
fantastic bargain. 



AUG 69. FET re-j.-Mi fof 3,5 f^H; ujj. F M 
j.rysi^! ^Viiuiiiiis. ?i('P ^«a«& umniijd. intrrjeiuic 
li-an IT) IC*. RT"IV \'iii\t^ g«rt, gOOtI 't>.'!>d T*.*" 

Ft 16tl*il rirof-aqniinn. Tfi^r K<[3lir^Ti=h.-i!i. 



tlL" 



-2 Ik 



SEPT 69. Ti 
^nlder509 '«i^l' 






i^ljUi 



ihcnrv. msy.i 
ri-a\/ttl Tliocry. 
. AM noise li 
aFSK g*n, Uaniistyr s-rrss deb-igging. n-!.e£rt|ji.a 

> *Cjacitct i.sijscie, i-adr^i ;Map3.5a:ic "i. A'.'! r-irvl 
pnT-^eT-tJi}". eJiT'^ vU^ litenss siiuiv li-an .^:, 
3 400? I ^ia:ir_ ATV viy I ;on =]~^t,i v -rans.^tJr 
^es^ers. F-TT ccmpfQssc^, rt pats 'h:ih ^ 

OCT 69. Super gain 4QM .ini, f-ET chirpcj-, 
lelephoriK in-fa, acOpie calLbiatui', thyrector 
Mii'ge prcii<K.ior. siOWUi luning rilCaa, identify 
calibrator i-itfi-mortlcs, F**," adapICir toi AM Ik, 
CS set* !jn ^tvS. pfoiioriiQJiaT iorm-oi xtel o.vt", 
>;j3i siltft* iiKtolio'ic'i. Ci ,^nuliiptii;i, i3-anjc*i vci 

NOV B9. fJC;< 3 .5:1 PAl - noun -tiLTc^s. y * 
."_iilltir,-tiM-. HV;77A a^ie^ndl V*^ D, 5M :Dr 
terter , 'nrjHi.-iB info, pi 7. SSric?^*!. 'm r- rnhllfc 

liinTs, uiTihrfdia ^ni, -132-0? r-ji Ijs^rt i;. [l^■.^' 
Si'jppiV trii;k5. wtrli dio^fos., traneistgr fcevwr, 
transialor bias desiorij Ktal vhl %jgn gen, cIeh; 
IrOnic '.'.-..rl.rbc, SB33 itiods, extra rjlaas studV 
;pari lOI. SBS^lJinca.- improv?n-ni»^ijs. 

DEC 69. Tr jn.g.i5tar'diarte ^l^i^ctwr, yLfn:,fr.v 
lo^u.'^im^uatDF, lufivU: ^il-T<n' «hahf:$. aiAndi 
s.VTehiria. S-.'ran 250 A? Tu 2, aSmft iale::iiwnT 
TiitiT 0>4fLi::^5. F-1I xial -jjl.bralti. irarrsia-nr ■:.>■ 
dwgn. fr- i^aji'e ti.. i 10 c-:z t r ^v)- ;i-.ti . i^B 
rig CI BM, tfa.trg ...iv-c sl-^dv r r' 11. lO?n 
hLjyers 3"'^^ 

JAW 70. Trrhnsceiuui itr.c.nssoi'/ 'Jfiil. Ejtnch 
power supply. SSTV KOlpr methocl. Eiase-unHd 
centci lo^ided ant. GM bandpasi tiller. eKir.d 
license stydv (pan 17. rectifier riiode use-iiti':. 
lac3imiPQ irlD. 

FEB 70. -SB ir>rn 1£-.- dpcle r.-.i cc.T..gi :i.r. 
l!i^ C?cn3<*f pt: S.'OJFO. ta-r-psr n"^L 5 hfTS. ■-■V 
*rft] ^Vi'htsieer. ai-'M'.''fi3;dB«>'5'"»fl ''o* -e 

PE0"R^"S. nX 35 moU*. MnorslT^ii arS' r^, VflS 



IC 



Q r 



vulufih' 



MAR 70. ado ap[jlu:ii!if>n^, chaj-ijar (or drycBlls, 
FM *req inst^i. pc Danrd consiru«:iiDh. ham fm 
BtsricJiffrflS, Lttaao irf Twann'»eTer. .Klud^si^req hn 
3j-t. '"i^"' »yi;«f^ morfjles (D*t \V, SiK w "VJ^i. 
n"- (dp iil^. {.'^Oiorola (1 1 V •(jni«rs-Gn, Hw. 
T}' ro*. tiivir^g 5_irpJiii» ic^ic. ^O 23A WRO 
hj3V <:En-jc*sior GftC*? i»-ia roiRver^lffTi . 
t'xtTa triads. ^;tjrfv I'.art 14!,* ^tfo :t> vn* ^r-t, 

APR 70. ^Jji'^e n!ar.:<<;r, 7 \j hoi..jr..Lir dic^- 

GOR riip'i-.iler, 7/Sw.ive 2M '..nl , t^slry .:I.im 
^iLJc'v (pan 1 5), liif(]t,nan5ive ■s^'niir.onduf^iorii, 
.■ffn-.nvarin/] turplus morisrs. iinmur 4i.m|s '.ji,ti 
■TtrgLitsior. hi j^orinriTHtncr. i1 Amp li iiqr. syiTni**, 

IjUx, yenDAl hii daL78 & T«i><ja1^ Flir^dl; ih iawn k 

MAY 70 C.:iii*ien'« f>-. ■!.m !fni:ka"," =rml1]3 
■',iP.i!e ot -■.'». 13I am rj« sl^^nir 'j.'fi vfxnt 
urifTHc^f s, L.i.ng 3W If^i^lis^nt IV aiuc U'jrir)laf 
jlariTia, p-jwi siippiiet ffijni surp »<l i^jinr^iorO" i-, 
"IF'' svito'i modiiins Ipnr-t 21, vfif FET ijcn 
,Trnps, adijiinicd ■■iriioi" iitfcs, nO'^i:.!''!'- ■Mini'^r' L.^; 

Hpvu-£Winf! tSOli-i'G rViUriilLir frtQ,-. \e ■..- -.y^, W -\ 'lll.d 

JUME 70. EJC-^^R ^r. ■■■'a l^ij :. irrmr.ie L:iwn 
n?iri.-3iD» iiwjlW If B*Bl-^l, l«vn ii cr> u k 
3i!^(¥rfln. i«m,[fro-Vin«tT ."i ^Diqv lau, 2 ol i-rfL' 

ZM:aiB3ir. asua cia,\5 tlu-d* Sp*i-T 17f 

DFC 70. ^Oiid^TJUO Vhi QKCltai, CHlH.l trc I ;..| 

ii-ol tor S3B, 2M ii.insisiui FM ix. HWlOO 
□ Jtsei :ur.inq. ■■Iiuli.- liPJifl'" d irx,--L-i , 3 50D2 hi 



JAN 71. ;;pL, 



"iiods. 



du 



IOT 



1 ]. 



ninft jiroiei-.Tinii. IC TX :icc«iMiry, :i>ii' ini'r 
«ojbl*! h.ii.irsyri WKceos, i^rntJFn'jnt ■..,(i..- 
Eoc; ham iicsiis* 1: uii'v i^iicaiirtTii 

J^EB 71. fi«rial Nit^lP- ■j^jHCtu- pn^C"V, ^FSK 
i-rii SSTV r-atifi ixf*. ATV l*inu. BTtY 

MHy iOi"/x'-tp!-, 55TV r-'.3i3n*j c rHiHacf Irti. ■•£ 
:oc(c n^r., EM 1* tiilWJ^r, fnin^vf'S' cIms *Vl^H.tV 

^pai-T 0!. RTTV irvuu, piirf hoard r.-:i :Tiiri;ii . 



MAR 


71. IC iud. 
^t iil^iis. ibju 

PUMS^fliiftAI 


,■ fi:: 


=1, IC 


lin 
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llil-PUla 

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mcrvi 
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rx/tx 


71, :rKo :■ 

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71. 75 V 




.1^ ,■ 


"■■■, 


2M 


r-i 


., 



irans-iicii ::sisr ll^J^l^^. TOM I'rVii i>-, VKLii'.a^in Iii!" 
iraiiAf (iivcT ikr'S^fliv fti^ilia iiBr-ijir«.su>r caip.p'*^ 

S -■T'p£ ui fll-Or, 1 TillD 2\1 ll-STE^- B.-fcPf. ■■."^1 ,K 

2F/- >irtw_r set;:, itHf '<"_i .jl c'.j-i'i v.aily ('^j.ir- M. 



2iVm...io. 



JUNE 71. 2M li::,jiii a«periiiii..niE 
multi l>and dipoly pauerns, ^vs 
vertical, pnckel liiycr. scri'Ckll'i, iwo t'' vlu, 

l.Liiii'Mi mobjtft ^'-'J^il^s. ^rftii'iHlOj' D*\'t «-^'J'IV. 

■cs^L.it ,1 v -lecdiJa tiri ■. ^OM lanv! jpi(. gi>?^.'r.i? 
::l3SiS tT,it^jy fiior *1l, 

JULY 71. IC .*uiHtil-jrfi^;.j' 3i.^iGsi:j:n- :-.v 
^lhd-_ ?M ^1'- Oit, 2Srt o iiiTw '.■S'ti::,i -M 
3'jri4^l.4r ^^ltt^o■'i', Molofc-s f* .3l-ip> convef-,?-?.-!! 

10;. 

AUG 71. HrjiTi lii-BinrrilB ipiii' 1 1. 50Q 'Mrr.r 
line-r, tlimensions TtM Jiify r.ull inefiv, "J lube 
SO/4 1 1 -11 ion. vf-J 'mCM leatjoi'l Ju niter on 1 TjM. 
t^p.itn-.u .-'.iss sf-!'.lv rr^j-: 11 ^ I'^'-i- TicV:>.-i. -.v.^^'-r 



SEPT 71. T,^„rtZ'---'.f-'S53 Pijy.'i^ ^uiJt.Me^.i<,l(R 
5!atfc iM imn-jpra. !C s.ihH ■i.iKioi, iw^ffl rt vj.*rt 
'iifl 12(5. iC ctpiipfess^jT ag^. 'TiuiilcTijjirjB- 
HT 20<3, i'an <i;ia.-rth¥ ^psi t'. sai.»ffl af 
maifirTij^c noisv. *.■'« wliK (-oiufcing irpif.er. y>!r- 
srsl in*.i3 .^tudv Cc art 1 2), transistor rtdat 
jmrkirg, IC pulsa gen, !onp-p.i:ch i50lsi.ion, htd 
wattmritar.? 

OCT ?t. cnififRKilEv *ep*ur« cd:. rrgnssBcver 
:.ia'n*^ lht>cilv. oiBtii'-iirig ■"ifiiicn liio-.'.eia, i5>bi 
s^^.*l^^:hl-p^iip, reib<EH3E<<jrrant bastBry r^isc*. 
7Ha-i^f i-tpeate-S. H^lh gfcufldii. 3J(i's> 'tslliK 

NOV 7t. 3 fll rr,\1 trfai'i. n^^to^ tiinr^,f ^nJ 
ptjLi". rr.' g^rn v«-[i:iiil, teansMT^r nrssmq, ■JT'li' 

siir^ ri;pcaLer. I'ii > h'jmi ng, uudio filTSi, ir:m 
sistQi /diudi: leaicr, xial :es!ici, GM kw .inij], 
10 15 20m nu-icS, Itansistoi- pi nen 1inj|. .int 
locdliiii-, t;oinn"jnn:;niQn5 dl^s, 2300 MHT ex 



AUG 72- sn'V ili;ro. £pe<i.M i^imcesKi^. *.*". 
refwjri" info, iT^I probe i^OPSti -jcikni, G= 
P'Oa'lr^ Ic 5«.»J5C'ly ^132 rt iK.T.r>s. pritan-a 

ir-pl'a. ?*j-ib"^ '."pfo. 5C^ i-feffi-jlarnr ^cr F(V^3. 
■"Itlaal" ;<r.gl p-v, 1^ rx srrapio'. auTo 'h-?:! 
alartr 

SEPT 73. PlLimLii-^on W cam^T-t, WWVB GO kk,: 
rn, ciQ.ir iLiue si3 (Jhti, ;;w active "£ i I tei , rl l-^-^l ing 
fit l2M:Jf;0O Gil.', ftalui-i .^m ■■t;E>rf. Tp-^nMs;oT 
t.'Dw-^ -iuffly. IC OM IV, 'C "m-flrrt dpMiVioi* 
■iVrfi ^1. gr\'„,^ i.not des^lfi ip.-^T 3>, *!..7nAW 

11 

OCT 72. Go- ..'.!• 'i far A^jg. i- r- a.,.nni-.--, 
2iV '■ri svnirfii--'- i^ii'-i 2l, 6".i lr-;-isi^<.' ■.!:», 
Tiina ,i'^iD>:re in.-U'' tim£ 1t*h measiff^-.-Kirt 
(pari it, aciiv^^ TJier design [par; 4;, repsat^r 

Uiiii>i, ■;«-;ra-clS,« O&A (tirjr: :l^, IjaSlnon v.r^r; 
icai, \Ci geri, time tJel^JV ""^'-"'V. 432 +ilr<?i ii,-ipHS, 
DC AC lovenflr, lic-cJinfic- convener, rrl diiiide- 
Slid iLiiKit driver. pliJS nrinus n>!.:npl v tor ICi. 



NOV 72_ H- U3.3.?<ic*^ Ljive- stj;* F^ttv 
^fti I . IC ft ti* ;*ar*.^«^C[' I'^vc. (^I'-r'^ntv 
r ^..f". 22P- MH.' p'^flfTt/i flcJb <^ i]*'ty an", 
s <'|: « iia-iiJiif^TW Atiir.a rv.^fr.ilai, Ti i™F leitw, 

■ liifiu^d I'.rpe" ase. 2IV1 lrn:( sy nthesiJtK- toarT 
31, K20AW ML,ni^r $rr^i.-l, 2M prHaiYitJ, e«lra 
c^oiS Q&A (rati 41. hi Z ■JtjlT-nLitei-, Nikcjiri Tesh 
siorv, whl 5wr Piinrpr, Tfan-^i&lur r-pgun ix, a22 
s:i*1 iransv^Mai, cC jro vl'-Moi , intrtj td fom 
i3iii!«r',. hviti-Tfl AT, rno,jj4lrfPnr MR l c>: modi, 
'OW iir^ntv.s^c- arri ix. dOW ^nd-i^^i. IC l&gj: 
d'^T-nmiraita. uvctlana ;api-'.;iian. ,1 -^ Li.-^^- 
^sncro^pr . ifen? Unso tatsiiwr^ niii ill - v t ,r [j. 

DEC 72. 3Srv *^q^H ^.ijJ;.'f»-. 2M fr- -^ tjj-^ 
l.-.i-ai triOG-iie' •itc! rtecniB'. uni-eraal 1 airo, 
i..!-i;i^.Ti!=H tiDisk^rtj, L-ySaDK inf.a, vuHiigo mbt 
iji-.f tn^ irifi, :'7J1 IS Afat! amp, SSS riiodijla 

[iOii monitor, st,->| freq/iitlivHy rTiftta'i-, 10A vsr. 
dt, stipplv. ti-^iismisslon lif'ft II9P5, radiy asiTon 
rnny, inpjijci.iifn.if ■nt^te:', >5 to 20M iiansvert5<- 

LED info. 40m iir^an-ip. i^ao^isioi -/fy. 397^ 

■ --.Jf^r. 2^.^ OPi.--.i 

JAN 73_ HT I'iv '■:-u.-'.-f-"f. 3 r^ 23-.- vt^-, 50 
fv'H? tr^^:^ .:^ .I'.ilf^, ^.e^..h. ?ii OT:&ig.-,-r M 'or-; 
5-1-.. t-n Ti??t !rti. jJh autM' •Lft-.a*-, SFjI i-cinvii-Tr' 
.i» -kg itc^TL-ftJi rsipeali* 4' 'Ills'. *'> twnd 
> nt^Jr. 'CM t^ ^.i^n^i-. il cjJe iiOiSt: li'.-iter. 
:-.<\.."-.-.li L*ge .^W22y Ifrin-i ^-lutr ■^Ol^.l mjfl. HAL 
in I .nod. 

Fea 73. ClJ\i Id gen. lo.kc otPPf'-^tpiri ,elsv. 
icwtjidijt lip^sUi-^lur?; flfiT, at.iive liltef, limp Ircn 
ni*a3Uf«[Vi«flt l(>an 2>. rfei^ifjilCi' Tirnn-.p p-:;r>iTcl. 
SSTV or^;v.i?* Iu*r1 H. 2M tOrt-.-er^r^^ -ps^-ia 
IPOjIOI, rT7iii|,tij,i, tlon iri\9'inq, Ft« l|i^5ir>3. 
1 ri(o »: ounxer c re^mp TR72 hi -jm (f-^i ficd, 
^^+^^|t-Dt H po>vir.3mt!C |pM! 1|, If^hf ni-TLh rt 
a^rivar ind^c-i^'s. 7^A4 ■')|-*a-5. f-ihsj- vijm.re 

ih^il. 

At*M 73. FVi .J. vi,glion .rip-Tt.-r, 2M FETurcamP. 
^^.yo 2M powver .-mips. r-ftpiMica toriroi !ioH 1}, 
r.-r^iiipr lic^in-.ipiy. Eurnpe.n. 2IV1 f iVi f n^ ficaivT-er 
:iri.i,i:r<' , RCA CVllJl ? rr;Od;, iiljh'.ninp fJvT-^^lOr , 
cjj .ilpyi--r-pr>T (Lidgffi. i.-anvi-jTOi v^ co^v^" j^ris 

*IJia*T 21, 'rpCdlkrt ALCproi^'ilp. J 

JUNE 73. 2-17 r-'H^ 5 c gf-ji, p ^t pc,-,.r -noTty. 
r..C-M--- tlccniir^ i'o_ PT'Y siii os-.-. ■! h. 40M 
■ivp«..i v;& f>, iti: p:i;ar n.ii.nT. 501523'.! 
rfi.io. <iO'%'A' Lfiunter mfi :i',. fitruLjre rimy sn, 
hiupi sun^nif: jtji], tone ili'i.iJtjer, fi^ild slf':?n3rh 
m«!T,yr. nif:Sd iMtttrV piJ' I", ohni rYi.->Ti:i , FCC 
r..-35 (Purl 1 ). 

AUG 73. Lo(j Kvnpxiics IL-jt- U. tonL- b if si 9&rp. 
il iTiij-^Wi an.f) rK-tion, Tinr'^i^lO' p-^dio i'r>T«>f i.o<Ti. 
ir4M pnr,. ii?51 V moniio--. l&iv iiosT trcq 
cmurilw. Vii*i1 fles^Ti,^*;|i -SOM ik, ^:ij MlHz 
lun^i<I^, TC^ audi^u prQCBis-*»o. P CC 'egs lusjt 3f, 

SEPT 73. *(irjK«:i*r tC'il-Ti' ^vsiB'r-. Itr£. 
piyrauirs U'larf 31, 2M -s CElibraiCT. !^:_L 1:: 
^ppliciiticnj, 1 "1 pad lioPhup, Hsa:h HW7'"?" 
rrtfcrer, Oscar-'R dopplor, "2M coax in I snt, 2M 

<.-privcrtBr. IC knycr, mossMry am Z. FC^C regs 

{pan 4K 

OCT 73. G£ -.sck'i:y-,^is -:,ci:-. "licrDL-z.iv..- Trsci 
-1"' jVLiiement. CA3i02e I'll? frtm:ci^'. 2 k.-. *il 
lp.w»r fi ivallp-int^x, ^.et*'' ecWiJi^r. GO. iO ri|i.>JlS. 
IC 'hi ■ cer.. i-'if f?sq rmJ^uni.or. FCC r^s luas 



r^-Vt-r? ii.i- u-, J''i-.> In i^TV 

ijLrnge mtiu.rnr, auttrf.:..!. h ccn 
THr ainplifi-ur. T R27 ,i.. lupnly. 
IC it-f lilTi;:. riionnentH3ir-V power 
<rt, IftOlVI iU'lt acpuplfti, Moto 
::tV tSB. CIJBSB af jrnp. PCC 



DFC 73. C, 1.- '.r^^J .-.. .■ 2;v- ■-.., ,.-,,. :C 

«^«iign. eeni^T,a«r] .oI:.iv5S1*j . prt- si^^'iHii *Qttirs. 
S*wiitE?i. iC im-iK, scM^LBniui ao'''^ cf^fmelm^ 3Mi 
fi*''j-taJ>i« £ji4di->, E'ffic^ronit: sAkh'^io- -nmih rw 
fff:LT rUrsig.i. FCC.7st\% Jpirr :i 



NOV 


73 


-JiQ 




::; r 




■ riniii 




IC IllH. 


mdn 


r ve 


r [i<:ril. 


f.iil.i 


J pr 


orr.ini 


rril.j 


H 1 


n'o. :; 


n-.r- 


Li.irr 


6! 



FEE 74. ySl.V nirtni 


al 1 


llo. IC ,HK 


lU 


l^l^ 


'^L.uph' si:-vffiei> iKfli. 15 


'2l>r-' 


vsrtic^l. 


?U!| 


lie 


lint- COPlrOl \V%ter^"', 


s^-- 


l^Mrd f.on 


11 II 


tiO 


var D .:J ^lliti. Lito^^i 




4U!i 




'.in ■j'liih r»*Tii 1«= -.r 


ciEii 


Pit. Itli-lfU^ 


l^T^T;ll^^ 


LfttTtiiTwisoi . iirtblH IC 


in. ' 


431* '.r ' 




-s>_- 


f.ly fpLFlSliHH hp-VIPW 


ipL-.i 


, f T,.g- -■■ 




■:;; 


tfni-l^r— sfl. WT. 










APR 74, VyT lo^ 


■- iriMi 


M'^5. :c'.- 


-1 • 


■.1: 


rc-.v, 1-" I'Mii^,.r,-tr>^. 


10 


>i ;;il- t:i .- 


IMIV 


e-li: 


p^ilicptti L;0r,Tit5l r-lr,^ 


tni 


•.innar. Hi: 


A 


r-i 


MMiny, '-.tH-.ni.idii.In lonc f|f.' 


1, FCC rr.'G 


l|.. 


rl ^ 


R^iprrprci- Atl.iy, 










MAY 74. &I .;:! ,y 


>,-i,, 


, .UlJlO . 1 


.,,, 


.^. 












li^irqkrr r.lr.r-.V 2 . 




.ir r in 


':=t 


-■^ 



JULY 74. - IIXIOA lrp-:;.ir, p =ii.-ri m( "Tri p* ■' 
jppv. ff.- afv ySf;. ijii3 :-C 1hi>«_ Hfl*;! fc'r*i«n 
r'..y. i 35 .11! ^52 rJt-^? OpiMini-S- 10^^ -lir- J^" 



4^0 



AUG 74. Iur.)i,l„l rlirB.:n...i .il \-Ji,-ir 
MM,^ FET |M,,,,mp, u.i... qdo to li'h.l '■;-, 
T-inrliinw ni pU'd l-iuokiii! H3eQ ^;^ r^:i(U2 ■ >: 
n'QUii. IracktrtH s w 1 flier, js'isl >/«>Hi.ni^Scii um 
5tf>l*ii "eg-jiatpiU aypLiI*. wi« icijn c&ifti^riBi, ni 
IhtJi-i.- fjiof.ilpni'.. inri tii'^r 

SEPT 74. tM.flK-'- .2r^' s.':-vi . " 

._■» ^.'(irr.tnfl iViM! ^ H, ..:! lC10:?i -i . -'acs 
.|rp *j\i a-" 11^, =■ ^-jn-u.f -iJi;-.!, ;k'".li roiif 
(ii'ii-.e^. -.■iix ^1*01 I'e or SSTV rtjr.-toi .iri^,t'fM 
iC ri:ster, n"r.r.i»r!..kre fin T- *Ji II r t. s t : cn». ravje: 
c U- 1 ^t ruction, irifmitc rl ull^nLjstOr, .■^kiCKOriiC- 



(More) 



216 



phoio f lasl 



IC "sclect-o-i 



OCT 74. MicroTfansisroi- =:!Jf.;uiTs, ty^lti'^ 
HT 220 (Diirt ll. T«peaTer govei nmstit. 
latcrt 5 vdc supply. Im selcal, removi 
mobile ants, Motorola metRnna. 2M ue' 
coUineai. Motoro!^ mooel torie, 2vi co 
dipole, 1,6 IVlH? if strip. MOSKE^Y slycti 
kev^r (fart 2], carbun m^ktj r.iM;Lii[. h,i sj 
lo pajs filler-, 6M preaiip, 



SVf 



l: 9ei 



, NCX 5 mods, mobile ■-■vli.fj !o 
Gliors, ssiv a=jtQ vertical! Triq 



r\fOV 7A. K20AW coun 
supply, wind direc 



laate. regulated 5 

__.^^,, _ _.. _.. .ndicaior. synrhe 

sized MT-220 Iparl 2). 20M 3-el beam^ aijio- 
patch pad hookups, double-stub ant iTiaTch, 
novice class mBtrucTionj dig! 5wr meter [part 1), 
6JV1 converter (l G MH^ if), ■■C-b^idge," 
MOSKEY electfonic ksyer ipart 3), Aug. sstv 
scan converter errara, repeater " ' - 
cor. 



off-tri 



There's little to get stale in back issues of 73 (our 
magazine is not padded . . , like others , , , with reams of 
activity reports), you or ''giftee" have a fantastic time 
reading them. Most of the articles are still exciting to 
read . . , and old editorials are even more fun for most of 
the dire predictions by Green have now come to pass, 
incentive licensing was every bit the debacle he pre- 
dicted , . . and more, Yoii'll really get a kick out of the 
back issues. 



S£P 76, The SM.iir^5 


r(i DDPP Law Moisc Ar-itnia losr: [I!, 


UllrKimcJIii Ri^uSalio 


wilh Mciv IC — Poner Supply Dfiigrt 


GfE3[lv Simplili'd, Cei 


.jfi IncJnoi An\ffr,fii\\<yh - Makin( ihiuEtet 




nuMsansiVL- 12 VoLis fo! Yojf Base Siailor, 


A Test Lili B5r3"?a - 


[Jsmgs Trori.iipr HsdiO. PfOWCl VOJI VHF 


Curiwntr - Muwi A 


rtcnra Rilav, Bidiculojilv ElmplB RTTY 




B CBsr^ A ^50 MHi Lansiflvfi^ f&, jMer 


5130, Spiicf! A^ Jurid 


ft 1 !. PROM Merrmrv flciikited. tglit T.ace 


Scope Adapter. The 


■riOWl. Zivpper. Sn-eaky Baudoi — kViih ^r 


ASC» i^tvbosidl. S. 


rpit Giauf-ici Tf:rm;nil - LJsirg suroliis. 



Cdu 



c rjot Wla^ic ■ 



* Sim pis. 



DEC 74. Care ut nicatls, wrnd speed/direction 
indicator, wk satelSite video converter, elec- 
tronic kever. hints far novices, onknown n-*etsr 
scales, SSTV tape ideas. TTL logic probe, 
p'jbiic service bar>d convei-ier, tuned diode les^ 
receivei-s, digi swr i-neTsr ipa^T :?}. lelephonc 
pole beam support, rhOiTibic antennas, 1974 

FEB 75. Heath HO 10 scope mod lOr SSTV, 
electronic key^r, dfgnal Mtetlite orbitsf timer, 
Oscar-7 ouersiion, Mtellite orbitaP predtttioo. 
Heeth Sei02 mods, conrip^ring FM & AM. 
reoeaier engineering. Robot SO-A sstv camera 
rnod, ne-jtralliing Heam SB-IIGA. "Sounce- 
less" IC switeln, tape keyer for cw tx. 

APR 75. S50 walkv for 2Mi, 2M scanning 
synthesizer, SS m H toroid info, S+unction 
repeater cOntrOlEer. nicad battery Precautions, 
TR22C preaiTip, teiephor^e aiiatiiimeni regs. 
Guide lo 2M Hand-held Transceivers, 2lVl 7-ei 
beam, basic Telephone sysTems (part 1>, lOmln 
ID Tsmer, modified bf Hu^tlp^ motiile ani foi' 
3M, 15M quad modified for 70t^, 7M collinHar 
beam, R-11A siirplus rx conversion, S/lGwave 
2M ant. Hallicrafcers SX Tl 1 rx mods. TeaJVl cw 
ix. 

AUG 75. 1 ^6/432 MH; Heiicsl ents (pj^r; 2J, %Q 
min lO timer, dfgi iwt computer ipart 1!, 
debugging ri feedback, DVM byers guide, wx 
sstellitG monitpr, cmos "accu-kev^r/' pc board 
n-hethad, sweep-tube final precautions, compact 
multiband dJpoJes, smaM digital clock, accessory 
vfo tor hf trar^sceivef. modern non-Morse codes, 
multi-function gen, 2M scanning ^V^lhSsiSer 
errata, KP202 walky Charger, TOM mukl 
eiementt be^r-ri. 

SEPT 76. Calculating freq tounter, wvx sa^eliiie 
FAX system {par^ 1), IC millivoltmeter, three 
button TT decoder^ troubieshooting s-srv pix, 
40M dx ants, 146/432 MHz helica! ants [con 
clussonir digf S^^vr computer (conclusion), reed 
relay for cw bk-in, ME555 preset timer, power- 
failure alarm, portable cirp rig power unit, 
precision 10 vdc reference standard, 135 kHz if 
strip, telepSione handsets with fm iransceivers. 



5ynihe?i?er (pari 10. ham radio PR). 

OCT 75. A deluxe TTY keyboard (part 1), 
Op Amps: a baste primer, an introduction to 
niicropracessars, 2m Synthesiser (conplu 
sionl, Satellite Fax Sy^ttm (concSusion), 
reguJated supplies (dispelling the mystery), 
Digital Logic made simple, FCC interview, a 
contest uP system, digital clock time bases, 
the operating desk, QHP 432, ham PR. 

ryOV-DEC 75. Bfockbuster doubt* issue! 
Flip flops exposed, breakthrough in fast 
scan ATV, strobing displays is coOl, the 
tuned !unch box [antenn-i tuner for HF 
transceivers), a deluxe TTY keyboard (part 
2), the 137- rotating mgst, less than $100 
multi-purpose scope for your shack (part 1), 
predicting third order fntermod, feedline 
primer, QRMing the Third Reich, why tubes 
haven't died, inatar^t circuits — build your 
own IC test rig, the K20AW synthesiser 
PRONrt-oted, a ham's intro to microproces- 
sing. Ground Fauk fnterrupter (a keep alive 
circuit for yourself), a $1 strip chart re- 
corder, an even simpler clock oso., the Fun 
City surplus scene, updating the Heath 
IB-nOl counter. 256 pagesi 



JATJ 76. CIqgKs 



U^^-,n VOL 



M<lfHi\ On COii., Ho- * ^^ »^ ., USif 

Kevbo.r.. l,.prc«0 V^-^'"^ ^^= ^^^ 
l.n!73.r.r,e"l»'3V-'';.o <|nc;gfl«1975rr, 



FEB 75. auiLd l StLrl^i-ul Cam muni;;] Im - rrKkXiL-;; Special 
Svmnp^iJl^iJ 'C Frw,.jenpv SiSini^fLi, Vo.i Can Malte Phcio PC 
2Dsrdi. Hov/5 Y^ur Sul-ecIi Q'jality?, ASCII w BnLdoi Ccuvcnor 
RTTV Aucsicall ■■ [he Dlgiial Way, Irnoio-'Ving Ifie FT-101. Nlghl 
DXmg or 10 jrd SSm, HuJilv SoLp 
VoMrSB-lOonieOrr, 



rVIAft 76. Sp<!Civjl SurUtiiu 



Snarl PoWfri SiiflpIV, H.JV-U 



Rcrjancv. Long 
TT DaQorter, One IC Tons 
h TTV firtnf:friifir,Thrt 



(WAV 76. ST>l:cl:^f Anxijnrs li5Ji; 

hEtix, An ASHwfid infcrtEd Vse, CI 

7!:--EtDrn Bio^dKindftf, The Magic c 
Yojr Arianr^j. 40.71 OXi 



If .1 Mbi 

Style, 



L- Sfll 



■Jil Sevens Micrg. 
2r. Hoiv 10 Con 



Veiy 



Ajnyietjr Weaitier Ssielliie Rerspiien, Ec^n Yiji 
ChEiu li'O - the ^lOciei l&.Cude Can^nQ' Usins PROMs. A r^ii 
C3H»T[e-Ctima-L[er Sfitsm, The lis nrd Oui; of TTL, Bu-ild a ( 
5;'S Wi^,"i Po..^jcr fo. Ytiji HT, &S5 T,™, S™;«o Circ 



r SSTV 









Langiiycjei -- Simpli 

JUN 7e. VHF 3| 
Twirh;n.n, Dfiiit..!.:, 
TV Tf^nsm liter, Ai 



igiijl of 


COLT3«!, 


[.Simplft 


ftmftCftiii 


MobllL- Au 


Wd'alci 




J3t T/pe 


■IMS. H,fi 


TI15K 


HEndfcM 


, ThoM 


OMs, Olt. 


ASCSI^ 



al - Super COF 
LJiiiiga C«i<:iLlsfai Pi 

:L.rTVRL-emvingJ.v^ 
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One month on!y-^ Any single issue $1 



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□ JUNE 63 
□AUG 63 
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• NOVICE STUDY GUI DE — Here is a completely new study guide and reference book for the potential ham. This is not a question/answer 
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• WEATHER SATELLITE HANDBOOK Simple equipment and 
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